What are the personality differences between Parakeets and Cockatiels

I have had a Parakeet before but Im thinking about getting a Cockatiel. How much different is a Cockatiel then a Parakeet? Are the personalities of a Cockatiel different then a Parakeet, and are they more active then a Parakeet?

I own fifteen parakeets and one cockateil. From what I can see, their personalities surely vary! Generally speaking however, it's quite hard to say that this type of bird has a so and so personality because each individual bird is different.

My male parakeets for example. One of them loves mating with all the girls and is obsessed with hands, the other is quite bouncy and enjoys jumping all over. Another one is quiet and laid back but loves attention, and then there's the one who NEVER gets in a fight (which my birds tend to do alot due to mating and/or possession issues). Then, I have the female parakeets. One is nicknamed the "dumb one" but her name means nothing since she's always the one trying to play games. Then we have the Wicked Witches, who are nice, but are always after all the boys and they have a tough bite too!

My cockateil on the other hand? He's timid around other birds, but he holds a strong curiousity and loves attention. When around my parakeets, he'll be a social butterfly towards his little friend (who sadly past away a few months back). He'll open up, and position himself so that you could groom him. He'll only do that to those he likes though.