To answer questions such as “what was the movie about?” “how did the game go?” and “what did I miss in class today?” you must be able to summarize.  Your questioner doesn't want to know every line and action in the movie, every play in the game, or every word from class;  the question asks you to select the important details and summarize them.  Similarly, when you summarize a reading you need to be able to find the important data and then present it as clearly and concisely as possible.