There are as many different Bingo card patterns as there are cards, theoretically.
Imagination is the only thing limiting what type of Bingo card pattern might be on a card. With that being said there are certainly several patterns that are far more popular, and therefore common, than most of the more outlandish patterns.
The most common Bingo card pattern that you will find, both online and off, is that of the straight line Bingo pattern. This pattern is very easy for card makers to produce and also very easy for players to play on. For those that might not understand what a straight line pattern is it is exactly what it sounds like. Now the line might be up and down. It might be side to side. Or it might be diagonal from one corner of the card to the other. It really doesn't matter, the object of the game is the same; to be the first to mark the line pattern on your card and call "Bingo."
A Bingo Game That Lasts longer
Another popular Bingo card pattern option is that of the "blackout." You might have played this version many times as a child and with good reason. The blackout might actually be the most exciting way to play because a player will have to mark every last number on their card to win. Of course this method of game play takes much longer to play than any another Bingo card pattern option but the wait is often times worth it. Also if you are organizing a Bingo fundraiser and don't have a lot of prizes to give away this might help you prolong game play while still keeping a high level of excitement.
Other Bingo Card Patterns
There are plenty more patterns than that. For example, if you have a certain affinity for numbers, not just the ones that are printed on the card, you can find Bingo cards with the pattern of numbers. For example if the card that you are playing on has a "ten" in the card you will have to mark all the numbers that form the number ten. The one will be marked and alongside it the zero will also be marked. Both of these numbers have to be marked prior to calling Bingo. Letters, lines, and pictures can be found as well. Most cards aren't all that large and the Bingo card patterns have to remain well within the confines of those small cards. The larger the cards that you are playing on will affect the patterns that you will be able to play on.
What it Means
The rules of the game never change and what it comes down to is that it doesn't really matter all that much what the pattern on the card is. Knowing the pattern is obviously important but outside of that the point is still the same; just have fun.