Using SSH

[Abielo]

Hi everyone!

So I have been struggling just a bit to under stand SSH. I know SSH can be used to have a secure connection from one computer to another. But I don't know if Im really getting the concept of an SSH Key, generating them and storing them safely. 

More specifically I am attempting to work SSH with Github.

Question

1. Do I have to generate a new ssh key each time I want to ssh to a github repository?
2. How can I make sure my ssh keys are secure?