Using the RSA algorithm
The RSA algorithm has become the de facto standard used in SSH and is employed by default, although it is possible to use additional algorithms. When it comes time to save the key you generate using RSA, you can use any name you wish. However, most people stick to the defaults:
The name of the file that contains the private key. This file should be readable and writable only by the owner and no one else. If anyone else were to obtain a copy of this file, he would be able to decipher all communications encrypted by your copy of SSH.
The name of the file that contains the public key. You can give this key to anyone you wish. Individuals will import this key into their keychains. Once a user imports this key, they can decipher encrypted text or files that you send to them.