Platform Bed Frame – Platform bed frames come in a variety of styles, and they either feature horizontal slats (think planks, usually wooden) or a solid platform for the mattress to rest on.
Slatted Bed Frame – A slatted bed frame is another way of saying platform frame and gets its name from the characteristic horizontal slats that support the mattress.
Slats – Slats are the planks that are usually placed horizontally on a slatted or platform frame. Their purpose is to support the mattress and their function is analogous to that of a box spring.
Solid Foundation – A solid foundation provides the support of a platform frame or slats, though it looks very much like a box spring and is used the same way: metal frame + solid foundation + mattress. Most modern box springs are solid or slatted foundations.