• See how apps affect Mac performance, battery runtime, temperature, and fan activity - Apple Support
https://support.apple.com/en-us/HT203184
Use Activity Monitor to check CPU activity, and other aspects of the Mac.
The Learn more section in main article above, has other things to look into.
..Read through the entire article; as links can go into detailed subtopics..
Depending on which system and build year model, certain things could be checked;
maybe SMC reset (power reset) and/or NVRAM/PRAM reset could help. Instructions
are detailed; and for newer portable Macs, some different steps are required to reset.
Some aspects of these resets may require trying more than two times; since they have
specific actions that must be performed to work. ~ If not correctly done, they won't.
Take care & good luck!🌞🐝