Would is a modal verb, a small helper word before other verbs. One common use imagines a result: If I had time, I would call you. It also makes requests softer: Would you open the window?
Two short examples
She said she would call me. Here someone talked about the future from a moment that has already gone by. Would is the past form of will, so it points ahead from that past point of view.
When we were kids, we would swim in the creek every summer. This would describes a repeated habit in the past. Note that this habitual use fits actions rather than states. It works for repeated events like swimming every summer, but not for conditions such as where someone lived, which English covers with used to instead.
Would you like a sandwich? This is a polite offer, and the same pattern softens requests too.
A nearby word that behaves differently
People sometimes mix would with used to, since both can talk about past habits. The difference is that would only works for actions, like repeated events you can picture happening again and again.
For states and situations, such as where you lived or how you felt, English needs used to: I used to live in Melbourne, not I would live in Melbourne.