What is microservice ?

 what is microservice ? 

As per Martin Fowler: 

It is an approach to developing a single application as a suite of "small services",

each running in its own process and communicating with light weight mechanisms,

such as HTTP resource APIs.

As we all know, today's world is being driven by powerful software applications which perform multiple operations in a few taps.

Be it any industry

banking, education, entertainment, job market, groceries, malls... and so on and so forth.

the list goes on, you name it!

So in this body of a powerful application or simply 'app' what runs inside the veins is not blood but "APIs" (Application Programming Interface)

APIs are nothing but a communication medium for passing messages (or more commonly known as 'data') between components of an app.

Now, earlier what made a software was the idea in which all the code bases was being written in the same large block. The code was not deployable in separate chunks.

Rather what was deployed was a single piece. Hence even the minutest of changes made to the code base had the potential of introducing a bug in the entire ecosystem.

This was bad in terms of User experience. For example, for an e-commerce application even if the check out component is not running that should not stop the customer from simply browsing the website. or it should not prevent the user to read reviews about the product.

Hence in order to be able to apply control on separate components in the app with complete separation of concern, we needed a different design pattern.

What was born is k/a Micro service

MS is a design pattern which is used in now a days technology.