Lang/en.yaml Need your help

Hello friend,
Just need a help like i have a requirement when in a single file i have
to
save all the messages and from controller n view need to call those
message,
so for this i had seen somewhere like we can create a lang folder inside
that we create a en.yaml file.
But seriously i don’t how to to use does any one tell me how to use
that?

regards
Abhishek