I heard that two different jerseys are used for offense and defense in american-football.
I heard that two different jerseys are used for offense and defense in
Is it so?
No. The whole team wears the same jerseys during the course of a game.
Given that the offense is the home team, you may be confusing the fact the offense is wearing their home jerseys (primarily their team colors) and the defense is wearing their away jerseys (primarily white). However, the offense represents one team, and the defense represents another team.
so there are three different jerseys used for a team(including
goal-keeper) in american-football, am I correct?
what about the jersey of players playing at center?
During an american-football contest, only one jersey is used by the entire roster of a team, no alterations. There is no specified “goal-keeper” in american football.