What is a “web service” in plain English?

Question

I\'ve been reading about \"web services\" here on SO, on Wikipedia, Google, etc., and I don\'t quite understand what they are. What is the plain English definition/descript

Answer 1

Webservice is a technology by which two or more remote web applications interact with each other over network/internet. It can be implemented using Java, .net, PHP etc.

Features of Web service:-

1. Using web services two or more systems exchange data over network. Data are exchanged either using XML or JSON.
2. Any web service has two parts Server end where the service is deployed and the client part where the service is accessed by its clients. Any web service can have multiple clients. When a travel portal is selling tickets of an airliner. Portal is client and the Airline is the server as it is selling its service.
3. Web services can be synchronous or it can be asynchronous also.A web application can interact with many web services but these web services are loosely coupled with their client web applications. That means any change in the parent application has little or no effect on the web services or vice versa.
4. Web services can carry attachment document also like PDF, Word etc. with its XML payload. Java provides separate API for this type of web services.
5. A web service always hides the internal complexity of the service to its clients. For an example, an airliner which is selling tickets via a third party portal is only gathering end user info via a web service and in return it is providing ticket. The portal which is selling ticket doesn't have to bother about the internal complexity of the airlines ticket reservation systems.
6. A web service can be of fire and forget type or it can return something. Suppose, a web application just want to send some info to a third party application. The sender doesn't need any acknowledgement from the receiver. In this type of scenario we need a fire and forget type of web service.

Answer 2

Web services are almost like normal a web page. The difference is that they are formatted to make it very easy for a program to pull data from the page, to the point of probably not using any HTML. They generally also are more reliable as to the consistency of the format, may use a different formal process to define the content such soap or raw xml, and there is often also a descriptor document that formally defines the structure for the data.

Answer 3

A simple definition: A web service is a function that can be accessed by other programs over the web (HTTP).

For example, when you create a website in PHP that outputs HTML, its target is the browser and by extension the human reading the page in the browser. A web service is not targeted at humans but rather at other programs.

So your PHP site that generates a random integer could be a web service if it outputs the integer in a format that may be consumed by another program. It might be in an XML format or another format, as long as other programs can understand the output.

The full definition is obviously more complex but you asked for plain English.

Answer 4

Simple way to explain web service is ::

• A web service is a method of communication between two electronic devices over the World Wide Web.
• It can be called a process that a programmer uses to communicate with the server
• To invoke this process programmer can use SOAP etc
• Web services are built on top of open standards such as TCP/IP, HTTP

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The advantage of a webservice is, say you develop one piece of code in .net and you wish to use JAVA to consume this code. You can interact directly with the abstracted layer and are unaware of what technology was used to develop the code.

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Answer 5

An operating system provides a GUI (and CLI) that you can interact with. It also provides an API that you can interact with programmatically.

Similarly, a website provides HTML pages that you can interact with and may also provide an API that offers the same information and operations programmatically. Or those services may only be available via an API with no associated user interface.

Answer 6

A way of sending a message to invoke an operation on another computer. The difference between web services and previous methods is what gets sent over the wire is standardized at a higher level.

Old way: describe endians, encoding, port numbers, etc. Web Service: URL, XML