To 'cut' is to delete the selected region but to keep a copy on the clipboard so it can be 'pasted' somewhere else. This is useful when moving parts of the audio around in the file.
To cut select the region and then press Ctrl+X.
To 'copy' is to make a copy of the selected region to the clipboard so you can paste it in another location. This is useful if you want to duplicate a part of the audio and insert (or mix it) in another file.
To copy select the region and then press Ctrl+C. To copy the entire file press Ctrl+A-C.
Paste can only be used after you have used the Cut or Copy functions (above) to take a selected region to the clipboard.
The paste function replaces the current selected region (or inserts if there is no selection). To replace a selection press Ctrl+V. To insert click on the position and press Ctrl+V.
Wavepad stores 10 current regions from the 'cut'/'copy' command into its memory. These regions can be pasted using 'Paste Cycle' one after another to a selected region by using the command repeatedly. The region which was selected just before the region which is available in the normal 'Paste' command will start the 'Paste Cycle'. Repeatedly using the command, the 'Paste Cycle' will activate the previously selected region in time. After pasting the region from the paste cycle, this region will become active in the normal 'Paste' command.
You can also Copy to System Clipboard (Ctrl+Shift+C) and Paste from System Clipboard (Ctrl+Shift+V). The System Clipboard can be used to copy and paste audio to and from other applications.