What are java maps ?

Answer 1

Map allow you to store data of type Key and Value.
For exemple a postal code with the code for Key and the town for Value. You can search by code in the map which will return the town.
See https://www.youtube.com/watch?v=uu20xO9AaU4.

Answer 2

https://www.sololearn.com/learn/Java/2181/?ref=app

Answer 3

thanks to all