Trips
Trips is three of a kind made with one card from your hand and a pair already on the board, which means the same three cards are available to everyone at the table.
The hand ranks identically to a set, and plays very differently. Because the pair is visible, an opponent can see the danger, and anyone else holding that rank has trips as well, at which point the kicker decides.
That is the practical difference worth keeping. A set is hidden and rarely shared; trips is obvious and often shared, so the same three of a kind is worth less money on a paired board than in a pocket pair.
an example
your cards
board
You hold one seven and two are on the board, so you have three sevens with an ace kicker. An opponent with 8h 8d has only two pair and loses. An opponent holding a seven with a smaller second card also has trips, and then your ace decides it.
This example is made up. The real one is in your own hand history: find trips in your own hands and see how often it came up and what it cost you.
related terms
Set
A set is three of a kind made with a pocket pair in your hand and one matching card on the board.
Kicker
A kicker is a card in your hand that does not form part of the pair or other combination, but is still counted when two ...
Nuts
The nuts is the best hand possible on a given board, the one no other two cards can beat.
next
Knowing the word is not the same as seeing it.
All ten hands in order, with how often each one turns up.