I found this page to be helpful in describing voices. Here's an excerpt:
Understanding Different Voice Types
A simple breakdown for recognizing vocal categories
Taylor Swift versus Alicia Keys. Justin Bieber or Usher. What makes one voice sound different from another? If you’ve spent any time in a chorus class, you know that there are different vocal categories or types (soprano, tenor, bass, etc.)… but what makes up a category? Well, a soprano is a soprano because she can sing high and a bass is a bass because he sings low, right? Not really...
And the link: