Link to ubuntu namse
 

I went to the download section of the mint's website, and notice the names have the same version name of ubuntu. I am wondering why that is?

They don't. There is no Ubuntu version 10, they have 10.04 and 10.10. There also isn't a version 11 of Ubuntu, the current version is 11.04.
That the version of Mint is currently 11 is pure coincidence.

No. I am sorry. You misunderstood me. What I am talking about is the package base name. Please click hear to see. Why does the package base says Ubuntu Natty, Ubuntu Maverick... Ubuntu 11.04 is called natty 10.10 is called maverick ect...

That is because Mint is a derivation of Ubuntu, so they share the same package base. You can use any package for Ubuntu in Linux Mint.

Ok thanks.