GitHub has introduced two-factor authentication (2FA) to enhance account security by requiring an additional authentication code, sent via SMS or a two-factor application, after entering a username and password. This feature protects against unauthorized access even if a password is compromised and affects various GitHub services, including GitHub.com, GitHub for Mac, GitHub for Windows, and API usage. Users accessing Git via SSH are unaffected, while those using HTTPS must use a personal access token instead of a password. In cases where a mobile device is lost, GitHub offers recovery options such as recovery codes and backup SMS numbers to ensure continued access.