As per this article : See how apps affect Mac performance, battery runtime, temperature, and fan activity - Apple Support
When an app isn't responding or working correctly, it might use more of the processor (CPU) than it should, even when the app doesn't seem to be doing anything. As the CPU gets busier, it uses more energy, which reduces the time that your Mac can run on battery power. It also generates heat, which can cause the fans in your Mac to spin faster.
To quit a process, first try quitting it normally. For example, quit Safari by switching to Safari and choosing Safari > Quit Safari.
If you can't quit a process normally, you can use Activity Monitor to force it to quit. Save any documents related to the process, then select the process in Activity Monitor and choose View > Quit Process.
If you don't recognize the name of a process, it might belong to macOS or another process that you do recognize. To see the relationships between processes, choose View > All Processes, Hierarchically. If you see that a process belongs to an app, such as Safari or Mail, quit the app before deciding whether to quit any of its processes.
To help avoid malfunctioning processes, keep your apps, plug-ins, and operating system up to date.
An according to this article : Use Activity Monitor on your Mac - Apple Support
- Memory Pressure: The Memory Pressure graph helps illustrate the availability of memory resources. The graph moves from right to left and updates at the intervals set in View > Update Frequency. The current state of memory resources is indicated by the color at the right side of the graph:
- Green: Memory resources are available.
- Yellow: Memory resources are still available but are being tasked by memory-management processes, such as compression.
- Red: Memory resources are depleted, and macOS is using your startup drive for memory. To make more RAM available, you can quit one or more apps or install more RAM. This is the most important indicator that your Mac may need more RAM.
- Physical Memory: The amount of RAM installed in your Mac.
- Memory Used: The total amount of memory currently used by all apps and macOS processes.
- App Memory: The total amount of memory currently used by apps and their processes.
- Wired Memory: Memory that can’t be compressed or paged out to your startup drive, so it must stay in RAM. The wired memory used by a process can’t be borrowed by other processes. The amount of wired memory used by an app is determined by the app's programmer.
- Compressed: The amount of memory in RAM that is compressed to make more RAM memory available to other processes. Look in the Compressed Mem column to see the amount of memory compressed for each process.
- Swap Used: The space used on your startup drive by macOS memory management. It's normal to see some activity here. As long as memory pressure is not in the red state, macOS has memory resources available.
- Cached Files: Memory that was recently used by apps and is now available for use by other apps. For example, if you've been using Mail and then quit Mail, the RAM that Mail was using becomes part of the memory used by cached files, which then becomes available to other apps. If you open Mail again before its cached-files memory is used (overwritten) by another app, Mail opens more quickly because that memory is quickly converted back to app memory without having to load its contents from your startup drive.
For more information about memory management, refer to the Apple Developer website.