Rebel

A rebel is a person active in rebellion, usually referring to paramilitary forces who take up arms against an established government. It often also refers to a cultural attitude which rejects normal, conformist attitudes, often for no reasonable cause, rather merely for the pursuit of a unique identity.

Often witin cultures, a sense of stagnation can develop, where the expectations by elders of the conformity of its young defies the instincts and natural intelligences of young people. The attitude of non-conformity with the establishent is usually characterised by said establishment to be disrespectful, thoughless, or inconsiderate.

The difference between rebel and terrorist is subjective. Likely, a rebel is someone who fights for a cause that is inline with the policies of the established powers, usually fighting for a cause such as democracy, or something resembling it.

A terrorist on the other hand tends to be someone who disagrees with you, and takes their point to the level of disagreeable action.