How does iPhone check software power consumption?

Apple's mobile phone can check the power consumption of each software as follows:

Tool materials:

An Apple mobile phone.

1 Open the phone desktop, find the settings, and then click in.

2 After entering the setting, pull it to the bottom position, and there is a battery option. Click to enter.

After clicking in, you can see the percentage of power consumption of each software.

Suggestion: Clean up the programs running in the background frequently, which can save electricity.