The Activity Monitor’s dock icon can be changed to a live tile that displays useful information. This makes it a lot more useful in the dock than most other icons, so it’s worth making a spot for it there permanently.
To do this, open Activity Monitor on your Mac. If you can’t find it, use the Command + Space keyboard shortcut and search for Activity Monitor. Once the app is open, it’ll appear in the dock. Right-click the Activity Monitor icon in the dock and select Dock Icon. You can now choose which data you value the most. The options include Show CPU Usage, Show CPU History, Show Network Usage, and Show Disk Activity.
After selecting the one you need, right-click the icon again and select Options > Keep in Dock.