Created by Jay Freeman (Saurik), Cydia was the "App Store" for jailbroken devices. Based on the APT (Advanced Package Tool) system from Debian Linux, Cydia allowed users to add (repositories) to download tweaks, themes, and apps.
If you are currently on a jailbreak that defaulted to Cydia (like Checkra1n or Unc0ver), you don't have to stick with it. You can actually install Sileo through Cydia. cydia installer repo sileo
The relationship between Cydia Installer repo represents the evolution of iOS jailbreaking from its legendary roots to a modern, high-performance ecosystem. While Cydia was the original pioneer, Sileo has emerged as a faster, modern alternative that can still host the "Cydia Installer" for users who miss the classic interface. The Package Managers: Old vs. New Cydia (The Legend): Created by Jay Freeman (Saurik), Cydia was the