As the dictionnary says, heros can have a lot of different meaning as it also can be all of them like a celebrity, a combatant, an adventurer, a great person, a popular figure and much more other names can be given to it. Heros in general, are people who have done something good to the society for exemple and people know him because of that. The same thing happens to rebels, they can be independent people, agitators, opponents, revolters, and obiously experimenters or all of it. They fight against rules, against the society, or politic etc.
The two words seem to be opposits but if you think a little bit more, you can see it is not totally right. A hero can actually have been a rebel first, like Martin Luther King who fought for the black people’s right and at those years could be called a rebel for fighting against the constitution.