The Uruguayan, 34, ended his months of speculation around his future by committing to another season at Old Trafford.
And Cavani has said he has built a 'huge affection' for United since joining the club from PSG last summer.
Speaking to MUTV, Cavani said: "To answer that question sincerely, about what the reasons were behind it and what is my motivation to stay, quite simply I would say it is exactly what this club represents, what Manchester United represents as an entity, as an organisation.
"That is down to the club itself, but also the people who work behind the scenes and within the club, obviously the supporters as well.
"As the days, weeks and months pass by, you do get to develop a huge affection for the club and I think, on a human level, it creates a bond with yourself, your team-mates and everybody who is part of the club, and you start to feel that.
"You notice that it is a real motivation and it gives you a desire to want to stay. I am very excited and keen to stay for another season, to give it my best, to help the club on the field as I can and hopefully bring some happiness and joy to the supporters."