sentence construction - What's the difference between "used to like" and 'liked'?

What is the difference between used to like and liked?

What is the difference if I say...

When I was 4 years old, I had one pink dress. My cousins used to like it (my dress) very much.

Or

When I was 4 years old, I had one pink dress. My cousins liked it (my dress) very much.