Total noob question about time controls

I just registered for my first tournament and, honestly, tried finding the answer on Google but still confused.  I am playing in a tournament that is: "4 round Swiss system tournament.
Time Control: G/90;+3".  Can someone explain this in words like you would explain it to your non-chess playing grandma.  Most specifically, I am assuming G90 means 'game in 90 minutes'....does this mean each player gets 45 minutes for all of their moves or 90 minutes.  Sorry for the dumb question.

"Swiss system" is method by which the rounds are paired (winners play winners, losers play losers, etc)

"G90;+3": Game in 90 minutes means both players begin with 90 minutes on their clocks.  The "+3" is three second increment. A player is awarded an additional 3 seconds on his or her clock after making a move.

Dude - you rock!  Makes total sense....wow, that seems long...do you know if most unrated players like me (i.e. < 1000???) use all that time or are games over in, like, 20 minutes?  Also, say I lose the first 3 games, does that mean my last game I would be similarly paired with someone who hasn't been winning?  (meaning - there's hope!!!!)

I usually paly 10 or 20 minute. 90 is kind absurd. the problem with 90 is what if the other guy walks away without disconnecting or resigning? then you half to wait 90 minutes. 

3 to 10 minutes is normal.

Yes, a common beginner mistake is to play too quickly. It's bad to spend 5 minutes on every move, but double-checking that a move doesn't hang a piece is very important.  Kids are especially notorious at playing way too quickly.  A lot of adults (like myself) fare well in slow time controls against stronger kids because the kids will just play too quickly and make mistakes.

As to pairing, yes - if you were to lose your first three games, you will be paired with players of similar standing (assuming enough players are in the pool for that tournament).

The OP is referring to a classical time control tournament.  Could be OTB or online.  Either way, this time control is standard for serious rated play.

If you are a beginner or a fairly low-rated player G90+3 is way too long. Such a time control is for very serious players with some chops. They know when to dive in for a long think, and they know how to use that thinking time to best advantage. Most lower-rated players exhaust all their possibilities within 5 minutes on even complicated moves. That's because they lack positional understanding and because they're not able to calculate variations more than, say, three moves ahead. So, yes, I would say that such games between 2 lower-rated players will be over well within the time limit. 

If this is an OTB tournament then please double-check that time control.  +3 is an unusual increment and you may have overlooked a digit.  Normally for a G/90 time control the increment is +30 (though some organizers may opt for +5 or +10).

In scholastic tournaments a common time control for the younger kids is G/25;d5 (5 second delay before time starts ticking off instead of 5 second increment always added even if less than 5 seconds is used).  In such tournaments it is not uncommon for the chief TD(arbiter) to announce the start of a round in the young kids' room, turn to head for the door to go the the next room and end up behind a few players exiting the room after finishing their games.

jetoba - thanks for the respone.

You are 100% correct!!!  I copied and pasted right from the website into this question, but going back after I read your response I went back and checked.....I was wrong - I must have highlighted and copied it incorrectly.  It is, indeed, 

Michael - I can totally see your point.  At my low level, I would expect my games to have a clear advantage by move 15-20.  Maybe I can use the time to double and triple check all candidate moves....I am wondering if it is considered bad etiquette to use a lot of time on simple moves - like if I take several minutes on a move that seems obvious.  Would my opponent likely think I'm being a jerk/bad sport.  I don't want to come across as disrespectful to the game or my opponent.

#11
"I would expect my games to have a clear advantage by move 15-20"
++ Yes, most chess games are essentially decided by move 30.
That is why you should play 90|30 at a pace of 3.5 minutes per move and finish on increment at 0.5 minutes/move.
It is better to have a won position with 30 seconds left on your clock
than a lost position with an hour left on your clock.

"Maybe I can use the time to double and triple check all candidate moves"
++ Yes, double and triple check and think carefully. Play as if you were playing for your life.

"I am wondering if it is considered bad etiquette to use a lot of time on simple moves"
++ No, not at all. You can spend your time as you see fit.

"like if I take several minutes on a move that seems obvious."
++ Always check and double check, now matter how obvious at first sight.
Especially never automatically recapture: often there is a better and unexpected move.

"Would my opponent likely think I'm being a jerk/bad sport."
++ What do you care what your opponent thinks? Chess is a game and the aim is to win.
You win by thinking deeper than your opponent.
When both players are of equal strength the one who spends more time can think deeper.

"I don't want to come across as disrespectful to the game or my opponent."
++ Disrespectful to the game is to rush it and not taking your time.

in chess "90 minutes time control"

is that much per player not the whole game

if it was the whole game then one person could think for a long time then their opponent has less time through no fault of theirs

When I was active in OTB chess 20+ years ago, Rapidplay tournaments were quite common with each player having 20 or 30 mins on the clock to make all their moves. I'm guessing these type of 1-day tournaments still happen(?)

So, slightly quicker but not so bad with increment, I suppose...

This can happen in RL games, too. You travel 40-50 km and you opponent does not appear. Then you have to wait for an hour. If your team travels by carpool even longer. If you play online it is annoying, but not that bad.

Oh, okay, it is some time now since I played OTB :-) Thank you for clarifying.

At least in the US the rules of the various FIDE-rated competitions almost always specify longer (usually an hour though 30 minutes is sometimes used).

I would like to play a classical game once

Very helpful info - Thanks...exactly what I was looking for