Why does my phone hang and automatically restart?

• Low main memory (RAM), corrupted system files, insufficient cache memory, Virus, System failure, or some Applications can cause Android mobile phones to hang or automatically power off / reboot (bootloop) or become stuck on the logo or boot screen during startup .Low memory, system failure, or application crashes are the most common causes.
• Switching between numerous apps, playing graphic-intensive games (after 1 or 2 hours), visiting the internet on the default browser using WiFi or mobile data, watching high-resolution movies, recording videos, and so on are all common uses for phones with limited RAM. Although RAM is not the only factor that affects performance, a poorly maintained software and a large operating system also have an adverse effect on the phone's performance.

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