How to make my phone last for longer time?

What should I do if my phone lags or hangs sometimes?

What is Game mode?

What is FBE Encryption Technology?

Why does my signal indicator shift from 4G to H every time I make a phone call?

What are the main specifications and features of iQOO?

What should I do if my device cannot be powered on?

How to register iQOO account?