One common reason for Macs running slowly is that programs are launching automatically at startup. To kill the process, type kill -9 followed by the PID number and hit Return.

When you find a process that’s using too many resources, locate the PID number to the left of its name. As in the Activity Monitor, this list shows your processes in decreasing order of how much of your resources they’re consuming. This will pull up a list of all your currently running processes. When Terminal is running, type top and hit Return. Launch Terminal (Finder > Applications > Utilities). You can also force processes to quit from Terminal. If it’s an application, it will remain shut down until you reopen it. If this process is critical to your Mac, it will restart. This will force the process to quit, freeing up the resources it was using up. To kill a task, select it from the list and click the X icon in the top left of the Activity Monitor window.Identify the heaviest processes or those that you don’t need running.By default, the tasks that are eating up the most resources will appear at the top of the list. You’ll see the tasks that are running according to the percentage of each resource they’re using: CPU, Memory, Energy, Disk, and Network. If a task crashes or is taking up too many resources, you can kill it from the Activity Monitor. Kill processes using Mac’s Activity Monitor

If your Mac is slowing down or acting up, it may be because an application or program that’s running in the background is malfunctioning. Mac Help Desk Optimization How to kill background processes on Mac?

Where to find activity monitor on mac