Does anyone use the P-K4 type of chess notation anymore?
The new way of notating - algebraic notation - has pretty much completely replaced the old way - descriptive notation.  Most people nowadays use algebraic notation, except old players who are very stuck in their ways.

However, there is still a purpose in learning descriptive notation:  reading old books.  Some of my favorite old chess books are only available in descriptive notation, so you have to be able to keep track of long series of moves in descriptive notation.