What is jailbreaking? - chillboi20/LegacyiOSGuide GitHub Wiki

Jailbreaking is basically when you remove restrictions on your device using exploits in the operating system. By jailbreaking, you can install themes, sideload custom apps, and make changes to your system otherwise not possible unjailbroken. Jailbreaking can breathe new life into otherwise obsolete devices, and make them more usable in the current era, like fixing older apps, clients for newer apps, and installing certificates for older services.