How do movies compare to live drama, both in the making of them and in the watching?
There is a significant difference between how movies and plays are constructed and experienced.
Plays are performed in real time. Actors usually spend a month or more rehearsing. They memorize their lines and practice every part of a scene until it is perfect. Once you are actually on stage, there are no "do-overs", and so the key to good acting is intense preparation by both the actors and the crew. While live performance limits some aspects of what you can do in a play (car chases are out, for example), actors can be more responsive to the audience, by adjusting pacing and atmosphere. Audiences in a theater have no distractions and are completely focused on the play for the duration of the performance. This allows playwrights to include subtle and complex ideas and relationships; the dramas of Ibsen, Chekhov, or Stoppard, for example, depend on this sort of close attention.
Films, on the other hand, are not shot continuously but are normally broken up into small scenes shot at various locations. While this allows a great deal of flexibility, it reduced the complexity of character development. Mistakes can be easily reshot, and so there is less pressure on actors to have every word and gesture perfect. As films include close-ups (unlike stage, where the audience is hundreds of feet from the actors), physical appearance becomes as or sometimes more important than technical acting skills. As most people watch movies at home now, audiences are more likely to be distracted, perhaps having dinner, talking, or playing games while watching. This means that rather than creating subtle effects, many movies go for blood, gore, slapstick, or other forms of obvious impact.