[DougBTX]

The technical difference would be that a keylogger logs keystrokes regardless of where the focus is, whereas normal "respond to key events" logic would be restricted to capturing key events in a field where the user understands the focus to be.

"Type to search" is OK, as the key events processed are restricted to the ones typed into the search field. A key logger would attach an event listener to capture key presses in any field, or even if no field is selected.

It is the same technical difference between a UI which has an explicit "paste" button, which reads from the clipboard only when that button is pressed, vs a web app which reads from the clipboard indiscriminately, in the off-chance that there's something interesting (a password for a different website?) stored in the clipboard.