Prescriptivism and Descriptivism 

Prescriptivism

The practice of one way or manner of speaking a language becoming more popular or well-known against another. This leads to view that some forms of a language are incorrect, improper, illogical, lack communicative effect, or are of low aesthetic value 

Its aims to create a standard language which teachers the majority of society as the correct language or way of communication.

Linguistic prescriptivism  prescribes culture which uses are socially proper and politically correct.

Descriptivism 

This is the work of  the absolute way of analyzing and describing how language is spoken (or how it was spoken in the past). Like science or maths, it's target is to observe language without a bias or a idea of how it ought to be.

Well Known Prescriptivists involve:

• Shadyah A. N. Cole
• Geoffrey Nunberg

Well known Descriptivists include:

•  Alexandra D’Arcy 
•  Merriam-Webster