Reply #2: "Tactile feedback" is feedback through your sense of touch.

[Tesha]

When you press a button in the real world, the button moves
and your fingers can sense that. Plus, many buttons provide
an "over-center" mechanism where once you've pressed them
far enough, they rapidly fall all the way with a click-like feel.
(Mouse buttons are like that.)

"Tactile feedback" on a phone tries to simulate that feeling of
"over-center clicking" as your finger presses the (mostly) non-
moving touchscreen. As the previous poster mentioned, it's
commonly done by briefly running the "vibrate" motor, but
folks have also experimented with using a piezoelectric "kicker"
attached to the glass of the touchscreen.

Some experiments have also been done to produce tactile
sensations as you swipe among the virtual buttons/keys on
the touchscreen. Done well, this is said to create the illusion
of raised key edges but I've never experienced this first-hand
so I can't day how well it works.

Tesha