This is an add-on over Android, which provides ample opportunities for customization of installed applications and the OS itself.
Previously, to fine-tune the system for themselves, users installed third-party firmware, often inferior to the official versions in terms of stability and security. With Xposed Framework you can significantly change Android without flashing the device.
Now it is enough to install this program on the device and connect the selected modules to it. Each of them allows you to make your own modifications: remove ads from programs and add new features to them, change the appearance of the interface, control the behavior of the device and so on.