The word Theropod is used to describe many dinosaurs. Theropod dinosaurs shared a number of characteristics:
-They were mostly all carnivores (meat-eaters) -They all used their back legs for walking and each foot had three toes -Most walked exclusively on two legs -They had hollow limb bones -The humerus (upper arm bone) is less than half as long as the femur (upper leg bone)
There are a number of other, more technical characteristics, but these are the basics.
Theropods are the stars of Jurassic Park, namely because they eat meat, and that includes humans.