What does it mean to change a visa status from b1 to TN?what is TN?

Question

What does it mean to change a visa status from b1 to TN?what is TN?

Answer 1

the only thing i can see is # Tennessee # or this :

TN (Trade NAFTA) status is a special non-immigration status unique to citizens of the United States, Canada and Mexico. TN status was created by virtue of the 1994 North American Free Trade Agreement (NAFTA). It allows American, Canadian and Mexican citizens the opportunity to work in the United States or Canada under a somewhat limited set of occupations. It bears a similarity:

http://en.wikipedia.org/wiki/TN_visa