Time question

I don't play chess I am too slow,  but I enjoy doing the puzzles. So I don't really know any of the rules of play. I recently watched a game on line to see if I could follow the play,  one of the players came late and only had 30 seconds left on his clock, needless to say now i wanted see the outcome of this situation. As I was watching I noticed the late players clock actually gained time after a move every so often.   This is my question , how does the clock add time .  BTW the other player resigned . And  no I could not keep up with the play.

If you play a time control that has increment like 3/2, that means that 2 seconds are added to each players clock every time they make a move. If they premove then they will gain time on their clock.

Thanks buddy, but pre move? so any move you make under 2 sec is added to clock?

The length of time it takes to move has nothing to do with it. How much time it takes you to move is deducted. Then the increment is added each move. 3/2 = 3 minute game with a 2 second increment. So if it took you a minute to make the first move, you would see not 2 min. but 2 min. and 2 seconds. if it took you 1 second the clock would read 3min and 1 second. I do believe you lose time on premoves, if correct probably hundredths/tenths? of a second.

Got it now Thanks.