What is Hard Reset?
A Hard reset, also known as factory reset or master reset, is a software restore of an electronic device (Such as mobiles, laptops etc) to its original system state by erasing all of the data (such as apps, settings, photos and contacts etc) that were previously stored on the device.
Another definition
A hard reset is a process of reverting a device back to the state it was in when shipped from the factory. Simply, Hard Reset is a process which deletes all mobiles data like photos, installed apps, settings and contacts etc.
If your mobile has any of these problems you must hard reset your mobile.
Freezing, Overheating, Stop responding, Poor performance, Unexpected stucks, Apps keep crashing, Suspicious device activity, Virus effect, automatically reboots or restarts, Shuts down without restarting.