How works Public-key cryptography on Github?

In Public-key cryptography is generated a pair of key, one private and one public, the public I put in the Github.

The Private-key decrypts the data and the Public-key encrypts the data. This means when I sent data to github this data is not encrypted because only Private-key decrypts the data?

Update:

Thanks guys, i'm understanding now.

I'm was thinking my data is encypted with that way in github when I send push/pulls. This case is used for login/verification/signing. That's all completely different from the encrypted transmission stream that the SSH connection sets up to send my datas.

Thanks everyone for your responses...