These commands on the Edit menu apply primarily to rows of grid inputs: elements, members, supports, loads, and load factors.
The Cut command (Ctrl-X) removes the selected row or rows from the grid, and copies them to the clipboard. This allows you to later paste them back into the same grid. The Copy command (Ctrl-C) also copies the selected row or rows to the clipboard, but does not remove them from the grid.
For the elements grid, if you select all the rows in the grid (including the blank row at the bottom for open shapes), the Copy command will copy all of the inputs for the part (thickness, position, etc.) along with the elements themselves to the clipboard. The Cut command will do the same thing, plus remove the entire part from the section. The clipboard part may then be pasted into different section as an additional part, instead of being pasted in as additional elements to the current part.
Similarly, Cut and Copy in the loads grid and load factors grid operate on the entire loading and entire load combination respectively, if you select all the rows including the blank row at the bottom.
The Paste command (Ctrl-V) inserts the copied row or rows into the grid at the current cell pointer location. If more than one row is selected when you paste, the selected rows are removed when the copied rows are inserted. If the current grid is for different inputs than those copied to the clipboard, you cannot paste into it. If the clipboard contains an entire part, loading, or load combination, it will be pasted as a new entry at the end of the list.
Since section elements, analysis members, and analysis supports may be selected in the graphic, you may perform the Cut, Copy, and Paste commands without using the grid in the inputs window.
In addition to the grid inputs, you may use cut, copy, and paste in text inputs with the shortcut keys Ctrl-X, Ctrl-C, and Ctrl-V.