Is Terrorism the same as a Revolution?

Although, the word "terror" has been around for a long time, and purportedly arose during the French Revolution, the word, "Terrorism", became 'common coinage' around the time of 9-11. It was first recorded in English, in 1866, as 'extreme radical and revolutionary groups' in Russia. However, its somewhat unimaginable, how an "extreme Radical" and Revolutionary groups", can be equated with Terrorism. Of course, I speak about a Democracy. In an established Democracy a "Revolution" is recognized as a "peaceable assembly". Of course, there are exceptions and many 'demonstrations' and 'revolutionary activities' can become 'extreme', and be less then peaceable. Nevertheless, they never reach a point where the term "Terrorism" is applied. Why is that? In Revolutions, the purpose is always to bring about a 'change in the Government', or, the "policies of the Government", or to establish a 'new Government'. What is the purpose of terrorism, and what does it hope to 'change' or to 'accomplish'? Terrorism seems to be for the sole purpose of 'terror'. It does not seem to have a 'political program'; nor an established political ideology, its pure unadulterated terror. Although its a prime example, of what 'many individuals' or 'Number' can accomplish, it has no goal and, hence, eventually, will 'self-destruct'. Every Individual is free to complain about his/her government, but to 'demonstrate' by causing 'terror' is not the answer. Every Government is composed of Leaders at the Top, and the Many, or Individuals, at the Bottom. The Top is what has to change in a Revolution, not the 'elimination' of the Many or the human race at the Bottom. It may be true, that without human beings, there is no need of Government, but that, would only mean that the 'goal of terrorism' is to eliminate the human race. How can it not self-destruct?