Microservices vs Web Services: Key Differences

In the early days of web application development, monolithic frontends and backends were perfectly fine. But the emergence of the cloud has changed expectations. Developers want to build applications that exchange information with APIs (Application Programming Interfaces). Business owners want faster development times. End users expect zero downtime. This new paradigm enabled the rise of service-oriented architecture (SOA) and, along with it, microservices and web services.

At first glance, microservices and web services seem very similar, and it may be hard to tell the difference between them. They both fall under the category of API representation tools. That is, they are both ways to deliver and share information via APIs. It's common to find applications that use both microservices and web services, but they serve different needs. The first thing to understand is that microservices and web services deal with different concepts in modern application design. 

In practice, however, both microservices and web services are important concepts in services-oriented application architectures. Understanding how both fit into the bigger picture of modern app design is essential.

Here are the key differences between microservices and web services:

• Microservices and web services are both API representation tools but serve different needs.
• Microservices focus on independent, loosely coupled services, allowing for flexibility, scalability, and faster development cycles.
• Web services enable interoperable communication between systems, making them suitable for integrating heterogeneous platforms.
• Microservices offer finer scalability and granular control, while web services handle larger loads and have simpler implementation and management.
• Choosing between microservices and web services depends on factors like architectural design, scalability needs, development approach, and interoperability requirements.

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Microservices vs. Web Services: An Overview

Some basic definitions of microservices and web services are:

• Microservice: A small, autonomous application that performs a specific service for a larger application architecture.
• Web service: A strategy to make the services of one application available to other applications via a web interface.

Looking at those definitions, the functions of microservices and web services can look the same. That's because web services can be seen as microservices in and of themselves. But they're microservices that strictly function on the web and other internet services. 

However, microservices and web services are not synonymous, and the biggest difference is in how they build application architectures. Here's a look at their respective architectural styles: 

• Microservices application architecture: A modular, services-oriented application architecture comprised of loosely connected, independently running microservices. These microservices usually offer APIs  (Application Programming Interfaces), so other microservices and apps can integrate with them.
• Web services application architecture: A modular, services-oriented application architecture where the applications that comprise the architecture connect via web services. Developers can use web services to connect microservices, monolithic applications, and more to form a larger application.

It’s common for modern, services-oriented application architectures to include a mix of microservices and monolithic applications. It’s also common for them to use a combination of APIs and web services to integrate the apps and microservices services that comprise them.

What are Microservices?

The microservices application architecture breaks a traditional monolithic application into its component functions. 

Rather than programming all application functions into a single piece of source code – as a monolith does – the microservices architecture isolates each function as small, autonomously-running applications. These small and independent applications are microservices, which typically run in a containerized environment.

This design philosophy is what is known as componentization. The major advantage of componentization is that all services of an application be deployed independently. In traditional monolithic development, all of an application's functions and services rely on a single large code base. Changes to the code can affect all parts of the application. But when services are developed as components, they are independent of each other and can be upgraded or replaced as needed without affecting the application as a whole.

A group of microservices that make up a microservices-based application usually interconnect with each other through APIs. When developing a microservices-based application like this, developers can use an API gateway – like DreamFactory – which offers an easy way to manage access to, and establish integrations with, the application's microservices.

How Microservices Work

APIs are the preferred method for connecting microservices because APIs support the widest variety of message formats (such as XML, XML-RPC, JSON, etc.) and the widest variety of message protocols (such as HTTP, HTTPS, MQTT, REST, and SOAP).

This flexibility in formats and protocols makes microservices and the microservices application architecture popular among developers.

As we’ll discuss in the next section, developers can also connect microservices apps via web services to form a web services application architecture.

Before we get into that, if you'd like a more detailed overview of how microservices work, please read our guide “What Are Microservices?”

Benefits of Microservices

Microservices offer several benefits that can positively impact your software development and deployment. With microservices, you can scale individual services independently, allocate resources efficiently, and handle varying workload demands effectively. Microservices also enable faster development cycles, allowing teams to work on different services concurrently and introduce new features and updates quickly. The loose coupling of microservices promotes improved fault tolerance and system resilience. Additionally, microservices allow for the adoption of different technologies for each service, promoting flexibility and the use of suitable tools for specific functionalities. The small, independent nature of microservices enhances modularity, making it easier to understand, update, and maintain individual services without affecting the entire system.

What are Web Services?

Instead of carrying out a specific function on behalf of a larger application, web services provide a standardized, web-based interface that makes the services available to other applications on the internet.

W3.org sums up the role of web services like this:

A web service is a software system designed to support interoperable machine-to-machine interaction over a network. It has an interface described in a machine-processable format (specifically WSDL). Other systems interact with the web service in a manner prescribed by its description using SOAP messages, typically conveyed using HTTP with an XML serialization in conjunction with other web-related standards.

Since web services allow various apps to connect and interact with each other, they are more like the glue that developers use to connect individual apps and build a web services application architecture. Web services are often equated with APIs as if the two are one and the same. A better way to look at it is that web services are one of the many representations of APIs. Artjoker Blog explains this distinction:

(A web service) is only one of the many API representations that use HTTP protocol for connection with third-party software solutions (for fairness’ sake, we’ll note that in rare cases, this connection is established via the other transport protocols like SMTP).

Another way of understanding web services is to view them as an “HTTP wrapper” around an API. This wrapper lets applications present their services through a web interface so other applications or microservices can interact with those services. Web services are popular because they allow this exchange of services and data, even when the connecting systems are written in different programming languages or running on different platforms. 

In this way, a web service functions as a bridge–regardless of whether the connection is cloud-to-cloud, server-to-server, server-to-premises, cloud-to-premises, or client-to-server. This makes web services particularly valuable for enterprises that want to connect diverse software components running in different locations.  

However, there are some conditions you’ll need to keep in mind when using web services:

• The applications and web services that comprise a web services application architecture need to share the same message format (typically XML or JSON).

• The applications and web services must also share the same message protocol (HTTP, MQTT, REST, SOAP, etc.).

Fortunately, an advanced iPaaS solution like DreamFactory can quickly overcome this lack of connection flexibility by converting messages from one format/protocol to another.

With that in mind, let's take a look at how web services work.

How Web Services Work

Here’s a quick overview of how a SOAP-based web service works to establish integrations between the application it offers services for and a third-party client:

1. The web service is a web-based interface that allows clients (or third-party apps) to access an application's data or services.

1. The client calls the web service by sending a series of RPC (Remote Procedure Call) requests to the server that hosts the web service. The advantage of an RPC request is that it doesn’t matter what language the client and the application are written in. For example, if the client is written in .Net and the application in Java, both can still communicate through the web service.

1. The web service responds to the RPC by returning XML data to the client. XML is a standard messaging platform that most programming languages understand.

1. When transmitting the XML document to the client, the web service uses the messaging protocol SOAP (Simple Object Access Protocol) and sends the data through HTTP.

Benefits of Web Services

Web services offer several benefits that positively impact system integration and interoperability. They enable seamless communication and integration between different platforms and technologies, ensuring interoperability regardless of the underlying systems. Web services follow standardized protocols, making them simple to implement and integrate into existing systems. This simplicity of implementation reduces development time and costs. Web services also enjoy broad industry support, compatible with various programming languages and frameworks, ensuring wide adoption and accessibility. Additionally, web services facilitate cross-platform communication, allowing different applications and systems to exchange data and services regardless of their operating systems or hardware platforms. Overall, web services provide organizations with interoperability, simplicity of implementation, cost-effectiveness, and broad industry support.

Microservices vs. Web Services: Key Similarities

Let’s look at the similarities and differences between microservices and web services from several different angles:

Service Specificity

A microservice carries out a highly specific service or task. This is known as "service specificity." 

The Facebook Messenger platform includes a microservice that handles file attachments. You can access this particular functionality by using Facebook’s Attachment Upload API. As the microservice exists specifically to handle the process of uploading and attaching files, this is an example of a microservice with service specificity that many of us are familiar with.

In contrast, a web service can offer one or many services from a single application. This allows a web services architecture to organize access to the different services provided by an application. 

For an e-commerce application, one web service could present customer-facing ordering and payment services, while another web service presents non-customer-facing inventory services. Even though separate web services offer access to these services, they belong to the same application. 

This is an example of how web services can help you manage and control access to the various services that belong to the same application and are not bound by service specificity.

Pluggability

With architectures built on both microservices and web services, developers can easily add, remove, and upgrade the microservices and applications that form a larger application architecture. This modularity results in a more flexible, agile architecture because upgrades are faster, cheaper, and easier to achieve without disrupting the entire application.

With microservices, the APIs that connect them offer greater flexibility because they support both HTTP and HTTPS, and they can establish connections between dissimilar message formats and protocols. 

Conversely, web services do not support HTTPS, and the connected components must share the same message format and protocol. That being said, an iPaaS like DreamFactory can easily overcome the message format and protocol requirements to ensure a successful exchange over web service connections.

Cost-Effectiveness

Microservices often run in containers. Since multiple containers can run on the same operating system kernel, this reduces costs by requiring fewer operating system licenses to run the various microservices that comprise a larger app architecture. 

Also, the universal connective capacity of APIs means that developers save time and money when establishing microservices API connections. This is because they can forego the labor required to build a hand-coded, point-to-point connection. 

Since web services are an HTTP-based presentation of APIs, they also forego the time and expenses of hand-coded, point-to-point integrations. 

Finally, the pluggable nature of both microservices and web services architectures makes upgrades faster, simpler, and more cost-effective.

Resilience

In microservices and web services architectures, the failure of one microservice or application is less likely to result in a cascade failure that affects the rest of the ecosystem. With both architectures, developers can implement a circuit breaker design pattern to detect service failures and prevent them from disrupting other microservices or applications connected to the system.

Language and Platform Agnostic

Developers can create both microservices or web services architecture by connecting applications running on any platform written in virtually any programming language. This allows developers to choose the most suitable languages and platforms for the different microservices, apps, and web apps that comprise an architecture. It’s also easy for them to establish premises-to-premises, premises-to-cloud, and cloud-to-cloud integrations.

Smaller Development Teams

Microservices and web apps allow for smaller, more focused, and easier-to-manage development teams. Managers can assign ownership of each web service or microservice to a small development team. This allows teams to work independently and with granularity, perfecting a single aspect of the application without the fear of coding conflicts with other systems.

However, it should be noted that web services development teams must stay on the same page concerning the common messaging formats and protocols shared across web service integrations.

Microservices vs. Web Services: Key Differences

Here are the key differences between Microservices vs Web Services:

1. Architectural Style: Microservices follow an architectural style where applications are built as independent, loosely coupled services, while Web Services adhere to a standardized approach for interoperable communication between systems.
2. Service Granularity: Microservices are granular, with each service focusing on a specific business capability, enabling flexibility and independent deployment. Web Services typically have coarser granularity, often representing larger functional components.
3. Development and Deployment: Microservices allow teams to develop and deploy services independently, facilitating faster development cycles. Web Services typically involve a more monolithic development and deployment approach, where changes may require coordination across the entire system.
4. Scalability and Performance: Microservices offer more fine-grained scalability, as individual services can be scaled independently based on demand. Web Services are typically designed to handle larger loads and may require scaling the entire system rather than specific components.
5. Complexity and Management: Microservices introduce additional complexity due to distributed systems, requiring mechanisms for service discovery, inter-service communication, and fault tolerance. Web Services are generally simpler to implement and manage, as they often rely on well-defined protocols and standardized communication mechanisms.
6. Interoperability: Web Services focus on interoperability across different platforms and technologies, making them suitable for integrating heterogeneous systems. Microservices prioritize modularity and internal service-to-service communication within a more cohesive architecture.
7. Flexibility and Agility: Microservices offer high flexibility and agility, allowing for independent development, deployment, and scaling. Web Services provide a simpler integration approach with standardized protocols but may have less flexibility for rapid changes or evolving system requirements.

Microservices vs Web Services: Which Is Best?

When considering the architectural design for your applications, it's important to evaluate whether microservices or web services align better with your specific needs. Both approaches have their advantages and considerations, so understanding the factors that impact your decision is crucial.

Microservices

Microservices are an architectural style where applications are built as a collection of small, independent services that can be developed, deployed, and scaled independently. They promote loose coupling, flexibility, and agility, making them well-suited for complex and rapidly evolving systems. Microservices enable teams to work on different services concurrently, fostering faster development cycles. However, they require additional effort in terms of service discovery, inter-service communication, and managing a distributed system. Microservices may be a good fit if you prioritize scalability, flexibility, and have the resources to manage a distributed architecture effectively.

Web Services

While it’s true that microservices and API connections are getting the most attention these days, there are some situations when web services are better for connecting applications:

• When organizing access to different services offered by a single monolithic application, a web service lets you create a service-oriented architecture that makes specific services from the monolith available through different web services. This helps you manage and organize access to specific aspects of the same monolithic application.

• Since each microservice has its own connection to a corresponding database, microservices architectures can be taxing on system resources when all of the microservices are constantly making calls to their databases. Conversely, a monolithic application requires fewer database connections and calls, which can save on system resources. With web service connections, developers can still benefit from a service-oriented architecture while simultaneously avoiding system slowdowns caused by too many database calls.

In general, web services work well for complex projects that communicate information over a network. They are also a good choice for bigger enterprise application environments because they can integrate between many other applications and platforms that might otherwise not have interoperability. Of course, business and project requirements should always be the determining factor when choosing the ideal architecture for any software project.

The choice between microservices and web services depends on several factors, including budget, implementation complexity, and specific requirements. Consider the scalability and agility needs of your application, the availability of resources for managing a distributed architecture, and the level of interoperability required.

Build Connection for Web Services and Microservices the Easy Way

After reading this guide, you should have a better idea of what microservices and web services are — and how microservices and web services-based applications are different. You should also be able to recognize the situations when web service connections offer a better solution than APIs.

If you’re in the process of developing a new application or IT infrastructure, the DreamFactory iPaaS can blow through your integration bottlenecks. As an advanced API gateway and web services connection solution, DreamFactory can automatically convert XML to JSON and SOAP to REST for web services integrations. Moreover, the platform features a point-and-click interface to instantly generate REST API for any system you want to connect.

Frequently Asked Questions: Microservices vs. Web Services

What is the main difference between microservices and web services?

The main difference lies in their architectural design and scope. Microservices are an architectural style where applications are built as a collection of small, independent services, while web services refer to standardized approaches for interoperable communication between systems.

How do microservices and web services differ in terms of scalability?

Microservices offer fine-grained scalability, allowing individual services to be scaled independently based on demand. In contrast, web services are typically designed to handle larger loads, often requiring the scaling of the entire system rather than specific components.

Which approach offers better flexibility and agility?

Microservices provide high flexibility and agility, as each service can be developed, deployed, and scaled independently. Web services, on the other hand, offer simplicity and ease of implementation but may have less flexibility for rapid changes or evolving system requirements.

How do microservices and web services impact development and deployment processes?

Microservices enable teams to work on different services concurrently, facilitating faster development cycles and the ability to introduce new features more quickly. Web services often involve a more monolithic development and deployment approach, where changes may require coordination across the entire system.

Which approach is more suitable for system integration and interoperability?

Web services are specifically designed for system integration and interoperability, providing standardized protocols and communication mechanisms for seamless interaction between different platforms and technologies. Microservices prioritize internal service-to-service communication within a more cohesive architecture.

How do microservices and web services differ in terms of complexity and management?

Microservices introduce additional complexity due to their distributed nature, requiring mechanisms for service discovery, inter-service communication, and fault tolerance. Web services are generally simpler to implement and manage, relying on well-defined protocols and standardized communication mechanisms.