this has been asked of me several times (not just by you Adam), so I am going to explain on the blog for curious non-fans.
In baseball - as we know- there is no clock. There are 3 outs per team per inning. The game ends when the leading team has recorded all 27 outs. If those outs are never recorded (i.e., if batters just keep on getting on base), then theoretically, the game could go on forever.
A no hitter is when not one batter reaches base safely by hitting the ball.
This does not mean that no one makes contact, that's only possible in that Brendan Fraser movie The Scout.
A no hitter is one where the pitcher records 27 outs without giving up a single, a double, a triple, or a homerun.
This has happened roughly 280 times in the past 130 years.
A no hitter does not mean that no one gets on base, merely that no one gets on base in the aforementioned fashion.
a game where NO ONE gets on base, is called a perfect game. It is one where all 27 outs are recorded with no interruption, no walks, no hit batters, no errors, no hits.
It has only happened like 20 times in baseball history.