Since the A37m only has 2GB of RAM, the userdata partition often fills up with "junk" that slows the system. You can manually simulate an "Auto-Clear" feature: App Management
: A significant portion of the 16GB is reserved for the Android 5.1 (Lollipop) operating system and ColorOS 3 . Users often find they have much less than the advertised 16GB for their own photos and apps. oppo a37m userdata
If the phone won’t turn on at all:
: This is the "home" for your apps, photos, messages, and settings. It is the part of the phone cleared during a factory reset or hard reset . Since the A37m only has 2GB of RAM,