7 "seasons", but think of it as seven movies, about that length each, and they can be watched that way, independently or in sequence.

Editing is not something viewers often notice, me included, but the pacing of episode 7 is brilliant. The editing does not draw attention to itself, but it sure flows and moves like it is alive like few other long form works. I pointed it out to a Hollywood film editor I was watching it with and she agreed the editing was excellent.

Helen Mirren is outstanding but the whole effort in all departments in all the episodes is so fine.