Someone correct me if I am wrong.

6 people are at a table

1st position - SB - Small Blind
2nd position - BB - Big Blind
3rd position - UTG - Under the Gun
4th position - MP - Middle Position
5th position - CO - Cut Off
6th position - Button - Button

Sometimes people add UTG +1, MP3 or something else to designate additional people sittng down.