How did the heroes of Greek myths resemble the gods and how did they differ?

The heroes of Greek myths looked like gods in power, but differed in that they were mortal and were most often born of a mortal and a god. Also, these heroes had compassion and understanding, while the gods rarely showed such qualities. Very often such heroes changed the course of the whole story. One such legendary hero was Hercules. He was able to perform 12 feats, for which he was able to get to Olympus and, in fact, become immortal.