Copy: Select text or files, then press Command (⌘) + C
Paste: Place the cursor where you want the content, then press Command (⌘) + V
Cut (optional): Select content, then press Command (⌘) + X
Paste with options (optional): Click and hold or right-click where you want to paste, then choose an option from the menu
Copy/Paste using the menu bar: Select content, then click Edit → Copy (or Cut) and Edit → Paste
Copy/Paste in apps (optional): Use the app’s Edit menu for Copy and Paste
Paste as plain text (optional): Press Shift + Option + Command (⌘) + V
Copy/Paste between apps: Copy in one app, switch to another app, then paste with Command (⌘) + V