It's not a dumb question at all. Illzoni has covered the technical points so I'll just add that hard court tennis is a sport where wearing good quality tennis-specific will cause you less aches and pains in your feet, ankles and knees at the end of a two hour session. It really is one of the few sports where trying to get by with running/skate shoes is a really bad idea. I learned this the hard way.
Yonex E-Zone Xi100 - Tournagrip XL - Adidas Barricades - Nike Tennis Socks