Do playstation 2 and PSP games are same ..............?  

I mean is there any difference in graphics,stories or in gameplay in both consoles..actually i am planning to buy a new PSP in exchange for PS2,because i think PSP would be better for me,so i can play it anywhere in the office as well where i get most of free time boring..but in Ps2 its impossible to play it because of unavailablity of Television set and it has lot of mess with its controller wires and cables ......