Here's a great little video that shows the difference between a standard tool change and a SMED tool change. SMED stands for single minute exchange of die, which describes the ultimate goal of reducing changeover times to a single minute. Faster changeovers allows for more changeovers, which reduces the amount of inventory you need to carry.
The video is short and sweet and uses lego blocks to get the point across. Nice interlude for your mold change reduction kaizen events.
The original video can be seen on youtube here.