Type 1 conditionals are used to describe situations that might or might be expected to occur in the future and are highly likely to actually occur.
conditional type 2 is used to describe situations that are unrealistic or have very little chance of happening. For example, imagine something that is not possible or daydream.
type 3 conditionals are used to refer to the past and suppose how the current situation could be different if what happened in the past is different.