in General, you can cut and paste NAMES of files, not the files themselves.
Actually Copying or Moving the files themselves is more complex, and requires Drag and Drop..
When you Drag and Drop a file on the same drive, the file is copied by adjusting directory entries, ONLY. No data blocks are replicated or deleted. To duplicate instead, hold the Option key, and you will see the cursor change to reflect the Optional action, such as by turning into a green PLUS [+] sign.
When you Drag and Drop a file between drives, the file is replicated by default, because there is a tiny possibility the file might be not copied correctly due to malfunction. If you indeed want to MOVE the file in one operation, hold the Option key, and the cursor will reflect that different option. In that case the source file will be replicated at the destination, then the source file will be moved to Trash (if possible).
A wildly under-appreciated feature of the Finder is the ability to, once a Source window is open, to use
File > New Window...
... to simultaneously open a Destination window. You can place the Source and Destination windows side-by-side, and Drag and Drop between them until you are satisfied.