A more thorough explanation:

A separate-property state is a state that has not adopted a community-property regime. In other words, it is a state where property acquired by one spouse during the marriage is considered their separate property, and not automatically shared with the other spouse.

The main difference between a community-property state and a separate-property state is that in a separate-property state, a spouse's interest in property held by the other spouse does not vest until either a divorce action has been filed or the other spouse has died.

For example, let's say John and Jane are married and live in a separate-property state. John buys a car with his own money, and the car is only in his name. If they were to get a divorce, Jane would not automatically have a claim to the car, as it is considered John's separate property.

Another example is if John and Jane own a house together, but only John's name is on the mortgage. If John were to pass away, Jane would not automatically inherit the house, as it is considered his separate property.