My way of explaining citation to my students: a citation is like the source's address--you're telling your reader where you went to find your information, and how they can get there, too.

1. Why should we care where in the world Bloomington MN Broadway 60 55425 East is?

2. Because when we have the address right 60 East Broadway, Bloomington, MN 55425 we can get somewhere awesome! © 2008 Cliff

3. You can get sources from ALL OVER the world. . . And your reader wants to know how you got there!