
click to enlarge
This tells you all the activities your computer is currently carrying out. The most important detail in this list is the fourth column, CPU usage. This tells you what percentage of your computer’s memory each activity is taking up. (There’s also a total figure at the bottom of the screen.) You can click at the top of the column to put the processes in order of memory usage.
If your computer is running particularly slowly, this may show which activity or activities are causing the problem. While some programs (such as video editing) will always take up a lot of memory, others (such as web browsers) may occasionally take up a very high percentage of memory because of a bug. It may be worth saving any work, then closing and restarting the program.
Most of the time, a process named ‘System Idle Process’ will be top of the list. Don’t worry about this figure or close the process as this is simply a dummy process which runs when the computer has spare memory. The process shouldn’t normally be included in the CPU usage total at the bottom of the screen.