Maybe for some a common mistake with domain level categorization

A top-level domain is ".com"
A second-level domain is "yahoo"
"www" is a gateway name to the network named yahoo : either a server or network node I presume.

I wonder if many ppl mistaken the top-level as 2nd? > http://answers.yahoo.com/question/index?qid=20060618110148AAXC7dV

So, would you like to buy a top-level domain; ".beer" or a second-level domain; "beer.com"

Disclaimer: I do *not own either of these domains! 
http://archive.icann.org/en/tlds/