For the last 10 – 15 years or so, most mattresses have been sold with what is now called a foundation. This is the part of the mattress set that used to be called “box springs,” based on its construction.
A contemporary foundation is basically a rigid platform that your mattress sits on top of. In many cases, your current foundation can be used with your new memory foam mattress. This is a great way to save money when buying a memory foam mattress in today’s tough economy.