Custom recovery refers to a process that allows users to recover their device or system back to its original state, by restoring it to a previous point in time when everything was working correctly. This is typically done using specialized software designed for this purpose and can be used to fix issues caused by malware, corrupted files, or other problems that may have occurred on the device. The custom recovery process usually involves flashing a new image of the operating system onto the device, which restores it back to its original state. This is different from a factory reset, as custom recovery allows for more advanced options and settings to be restored.