The difference between the two terms is that relationship property is all property acquired by either partner during the relationship. This includes your home, cars, household furniture, and appliances.
Separate property can be property owned before the relationship, inheritances, and gifts from others, including from a trust.
If you and your partner are to separate after living together for more than three years, then all relationship property will be divided equally between you. It is important that you take the appropriate measures to get a contracting out agreement if you deem it necessary. That way, the assets you consider as separate property, will stay as yours after a relationship separation.
At Gallie Miles Lawyers, we're here to speak your language so if you have any other questions or things you don't understand, feel free to reach out.