I dont know anything about python. Can anybody tell me what is this??
Is Google broken ?
Yep, Google is a wonderful tool, try a Google search on;
'Why Python language is used?'
Of course ask your question in a Forum where Python is supported, this is an Arduino forum.
It is a widely used scripting language. Grammar is very easy to learn. Tons of widely used libraries for almost any task that one might want a library for.
It is very popular as a language for applications on a computer that communicate with an arduino over serial, for example, to gather data sent by the sketch running on the arduino, send instructions to the sketch running on the arduino. The popularity owes to the ease of writing python without much of a learning curve (since people using it to communicate with arduino are usually more interested in code running on the arduino itself, which is often more complex and harder to write), availability of libraries, and the speed with which this sort of simple script can be written.
There is at least one project (circuitpython) on more powerful microcontrollers than most arduinos that is meant to allow python code to run on the microcontroller itself; this is beyond the scope of these forums, though - whoever is running that (was it adafruit?) has resources and a forum for that.