Copy puts selected text on the clipboard and leaves the source text. Cut puts selected text on the clipboard and removes it from the editable source. Paste inserts the clipboard text at the insertion point, or replaces a selection. This simple model holds one clipboard item and adds no automatic spaces.
Worked example
Source: MOON. Copy all four letters and paste into an empty label: both places say MOON. Cut the four source letters instead and paste them: the source is empty.
Two Separate Label Experiments
Experiment A starts with STAR in Source, an empty Label and an empty clipboard. Select all four source letters, Copy, then Paste into Label. Experiment B starts over with the same initial state, but uses Cut, then Paste. Each experiment is separate. No typing, automatic spacing or synchronization happens. These are editable text boxes, not file-manager operations.