We use the present continuous tense to talk about the present.
for something that is happening at the moment of speaking.
for something which is happening before and after a given time.
We use the present continuous tense to talk about the future.
for something which has been arranged or planned.
We can use the present continuous to talk about the past.
When we are telling a story.
When we are summarising the story from a book, film or play etc.