Differences between Web Services and Web APIs
Web services and APIs are two overlapping technical terminologies that are sometimes misunderstood. You may have seen these terms used frequently, but are they really interchangeable?
While they do have some overlap, web services and APIs are still two different concepts.
Web means HTTP protocol, and Services means request-response. Web services are a stateless protocol (we send a request, receive a response).
Web services are mainly based on distributed computing technology. It provides a standardized way to communicate with different applications using open standards such as SOAP and WSDL. Web Services have the advantage of allowing applications to be created in a variety of languages while still communicating with clients and servers via transferring data.
Web services can be:
- Developed by one company,
- Used by another company, and
- Hosted by a third company
An application programming interface (API) is a set of routines, data structures, object classes and protocols provided by libraries and operating systems to support the building of applications.
It's a software interface that serves as a link between two programs, allowing them to interact. It allows web servers to easily and quickly interact with various third-party applications and services.
APIs Vs Web Services
API and Web services both serves as a bridge for communication. Let’s look at the differences that distinguish one from another:
- API mainly acts as an interface between two different applications so that they can communicate with each other. An API specifies the mechanisms by which one software programme communicates with another. An API generally involves calling functions from a software program, and when this action involves transferring data over a network, the Web services come into play.
- A Web service is nothing more than an API encased in HTTP. An API doesn't have to be web-based all of the time. An API is a collection of rules and requirements that a software programme must follow in order to communicate with other software programmes.
- The API used in Web apps is also web-based. BA and COM-based APIs are used by desktop apps such as spreadsheets and word documents and they do not require the use of a Web service.
- All Web services are APIs, but not all APIs are Web services.
- Web services may not be able to execute all of the operations that an API would.
- For communication, a Web service employs just three styles: SOAP, REST, and XML-RPC, but an API can use any style.
- A Web service always needs a network for its operations, whereas an API does not need a network for its operation.
Frequently Asked Questions
Q1. What are the components of a Web Service?
Ans: The three main components of a Web Service are:
- SOAP (Simple Object Access Protocol)
- UDDI (Universal Description, Discovery, and Integration)
- WSDL (Web Services Description Language)
Q2. What are some different types of API?
Ans: There are four types of APIs mainly used:
- Open APIs/Public APIs: These types of APIs are publicly available and can be accessed by anyone.
- Partner APIs: Unlike Open APIs, these APIs are not publicly available, and developers require a license to access them.
- Internal APIs/Private APIs: As the name suggests, these APIs are mainly only for internal usage within an organization or company.
- Composite APIs: Composite APIs are designed to bundle multiple API requests sequentially into a single API call.
Q3. What are some real-world APIs?
Ans: Some real-world APIs are Google Maps API, WhatsApp API, Facebook API and Twitter API.
APIs and Web services are used everywhere, from social media to businesses, and are integral to most modern applications. In this blog, we learned about Web services, APIs and the major differences between them.
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