There are more than arrows in Unicode. They have different functions and play different roles. All simple single-headed or double-headed arrows can be implemented by different character encodingsare of 8 directions: 2 horizontal, 2 vertical and 4 diagonal. If you are intrested in the meaning of any arrow, you should mouse over a symbol to see its name. Also you can move to the page dedicated to that symbol. Arrows can indicate force directions in Physics, they can be used to point directions in public places or as Maths symbols.
How to Read a Spool Valve Schematic Drawing | RealPars