
Formations. What are they? What do they mean? Why so many numbers? And so forth. As part of a series I'm going to be doing on this blog explaining some of the ins and outs of soccer to new fans, let's take a look at formations. (Thanks to Tom in my email for posing this question!)
So. A formation is how the 10 field players on a team line up. (The goalkeeper is your freebie, as he or she will always be in goal. Easy to remember!) There are a ton of different kinds of formations, and in the end, players travel all over the pitch during the, at times, chaos that is a soccer match. So it's more of a guideline that shows how a team wants to play – more attacking or defensive, mainly.
First off, you'll notice the formations are numbered. As seen below (big up to lineupbuilder.com):

While players' shirt numbers have become, like many sports, just that player's favorite number or whatnot, some numbers still hold special meaning, and it can be traced back to how teams used to line up on the pitch, when the shirt number equaled a player's specific position. Here's the basic breakdown:
No. 1 goalkeeper
No. 2 right-back
No. 4 right-side center-back
No. 5 left-side center-back