Is there a difference between a cage sprung mattress and a pocket sprung mattress?

Pocket springs have revolutionised mattress manufacture in the last few years. They are individual nested springs each in there own cotton pocket. As the springs are individual they move independently of each other accenting your body's movement and supporting you only where you lay. Also if you share a bed it reduces the 'Roll-Together' effect, this is where two people of uneven weight unintentionally roll together, it can usually happen with a standard cage sprung mattresses where all the springs are linked.