Activity Monitor copy 

Activity Monitor displays information about all the processes running on your Mac, including CPU, disk, memory and network usage. You can see exactly how your computer’s resources are being used via a searchable table, helpful graphs or even directly in the Dock icon. You can view the processes organised in different groupings, quickly search for processes, and quit them. Activity Monitor also makes it easy to see how your memory is being used and how much memory is available, as well as disk activity and data transferred over the network.