When should I use Cascade Update / Delete???

Can anyone explain this to me for SQL 2000?

Thanks

it's the same as in any other database. When you have a table reliant on another table then you can use the cascade method which should ensure database integrity.

Typical example might be an order header table with an order line table. If you delete the order header, then cascade delete on orderline would make sense, since you dont want the lines to exist without a header.