From The Free On-line Dictionary of Computing (19 January 2023):
click
<hardware> To press and release a button on a mouse or
other pointing device. This generates an event, also
specifying the screen position, which is processed by the
window manager or application program.
On a mouse with more than one button, the unqualified term
usually implies pressing the left-most button (with the right
index finger), other buttons would be qualified,
e.g. "right-click". Multiple clicks in quick succession,
e.g. a double-click, often have a different meaning from slow
single clicks. Keyboard modifiers may also be used,
e.g. "shift-click", meaning to hold down the shift key on the
keyboard while clicking the mouse button.
If the mouse moves while the button is pressed then this is a
drag.
(1995-03-14)