علوم قرآن و حدیث

Used to
- Indicates a repeated or habitual action in the past that is no longer true
- The action occurred for some time in the past and then stopped

Examples
I used to smoke when I was younger. (But I don't smoke anymore.)
They used to live in New York. (But now they live somewhere else.)

Would
- Indicates a repeated or habitual action in the past, with no implication that the action has stopped
- Simply describes how things were in the past, without suggesting a change

Examples
He would wake up early every morning
They would go for a walk after dinner

So in summary

Used to implies that a past habit or state is no longer true, while would simply describes a past habit without any implication about the present