Afghan Taliban are genuine domestic resistance, they are against US because its a invading force and is illegally occupying Afghanistan.
TTP is a mixture of many armed groups having somehow a same UN-ISLAMIC ideology, of course they claim otherwise. They were formed by the local Militants because of some disputes with the Government but in a year time it transformed into a full-time Terrorist organisation after Baitullah Mehsud took over the command, they have a agenda to destablize Pakistan, collaborating with hostile Intelligence agencies, NOT attacking American Forces at all, not a single incident reported as that, Mullah Umar even issued statement denouncing their actions and calling their activities against Islam, because to him, fighting a Army of a Islamic state is not a right thing and suicide bombings in Pakistan are unjustified.
There are many evidences that TTP is a group of illiterate monsters who are just liable to death! No other option for them, even Islamic scriptures suggests severe death penalty for rebels like them
And Al-CIAda
No on actually knows it it really exists, a new group is formed in a far country and they blow up a building claiming that they are Al-Qaeda, in reality, its existence is highly disputed, Al-Qaeda is more like Uncle Sam's propaganda machine, they provide them excuses to attack different countries.