The defender moved to Dortmund from Freiburg for a reported €10 million this month and will provide competition for regular centre-backs Mats Hummels and Neven Subotic.
The 20-year-old is confident the move to Signal Iduna Park will help develop his career, accepting that he is prioritising playing at the top level over consistent competitive gametime.
"Sure, I could have stayed with Freiburg for another season but I want to take the next step in my career," Ginter told Bild. "Everybody wants to train and play at the highest level at Dortmund.
"With all respect to Freiburg, everything is much bigger [at Dortmund]. Dortmund can win titles and they are a strong team pushing to win the Champions League, which is why I want to play my here.
"I had very good talks with BVB's officials and, although I will not play every game, I have signed a long-term contract."
Any suggestions that Ginter was brought in to fill a soon-to-be-vacant hole in BVB's defence should Hummels be signed for €20 million by Manchester United this summer were flatlined on Tuesday by coach Jurgen Klopp.