Components are seperated speakers that use crossovers to split the frequencies.
So you have a tweeter in its own seperate unit, and a mid bass driver on its own. Both are connected to a crossover. The signal goes into the crossover from the head unit, and is split passivley or actively (depends on the type of crossover - commonly passive) to the appropriate speaker.
The advantage in doing so is you get a better more flexible sound stage from them as you can position them in a way you want to suit the car. Also as there are no cuts out of the cone, they're generally more rigid thus giving better sound.
Hope that helps and if i've misinterpreted your question i apologise