^ +1
I generally explain to people it's like a highway. Each core is like a highway lane with a speed limit. For example, let's say the speed limit on a highway is 80MPH, let's also say that there is 4 highway lanes.
Instead of the 4 highway lanes merging becoming one big 'super' highway with a speed limit of 320MPH, all 4 highway lanes are running at 80MPH.