The clipboard is a temporary storage area the memory where the operating system keeps the content you copy or cut and paste to another location. Clipboard basically acts as an intermediary between the copy/cut and paste operations. When you copy or cut any data, the data is stored in the clipboard.
In macOS, you can always see the clipboard data or clear clipboard. This article will explain the process of checking clipboard data and the steps to clear the clipboard.
How to see clipboard data on Mac
Before I tell you how to clear the clipboard, let me tell you how to check the content of the clipboard.
First of all, Open Finder. Now go to the Edit menu and click Show Clipboard. It will show you the contents of your Mac clipboard.

How to clear the clipboard
You can clear the clipboard content using a Terminal command.
Open the Terminal on your Mac. Then type the following command pbcopy < /dev/null in the Terminal and press Enter. This will clear the clipboard content.

Alternatively, you can restart your Mac. After you Restart the Mac, it deletes the clipboard content completely.
If you want to boost your productivity, you can also start using a good clipboard manager such as Paste. This clipboard manager lets you keep multiple items in the clipboard and paste whatever you want. Unclutter is also a good clipboard manager for Mac. It lets you manage clipboard history effectively.