meaning - what's the difference between did and was doing?

Here are examples of the sentences. What is the difference between them? They seem to be almost the same to me so I don’t exactly understand the difference.

We worked from 9:00 am to 5:00 pm yesterday.
We were working from 9:00 am to 5:00 pm yesterday.

When we came home, she talked with her friends.
When we came home, she was talking with her friends.

I slept when the cat came in through the window.
I was sleeping when the cat came in through the window.