There are several types of clone URLs available on GitHub. When you view a repository while logged in to your account, you will be given the relevant URLs in the sidebar:
https:// clone URLs are available on all repositories, public and private. They are smart, so they will offer either read-only or read/write access depending on your permissions to the repository. You will have to authenticate using your GitHub username and password to push to a repository you have write permission with and to read from any private repository you have access to.
Use these URLs for users that are behind a firewall or proxy. Many firewalls will block the ssh URLs from working.
Tip: You don't have to enter your password every time you use an HTTPS URL, check out this guide for more info.
These URLs provide access to a git repository over SSH. To use these URLs, you must have an SSH keypair generated on your computer and attached to your GitHub account.
Use these URLs on your production servers for deployment. You can also use SSH agent forwarding with your deploy script to avoid managing keys on the server. Users that are familiar with SSH keys may prefer these URLs over HTTPS.