Problems with ssh and git

ssh
git

#1

Hi, all i work with github and c9.io
In github you can deploy ssh key in “you project / Deploy keys” or “Settngs / SSH and GPG Keys”. What is the difference?

Actually i have only one workspace active. In this workspace i have 5 projects. Every project have a repository on github.
And i generate ssh key with this command : ssh-keygen -t rsa -b 4096 -C "your_email@example.com"

The firt key ive genrated and associated in my first github project works. But after, when i work on the second project doesn’t works.

error message :

Warning: Permanently added ‘github.com,192.30.253.113’ (RSA) to the list of known hosts.
ERROR: Permission to salimbenfarhat/toy_app.git denied to deploy key
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

optional: what is the role of the file “known_host” and “authorized_keys” ?