Make a clone of an object with Illustrator

Question

I'm making a big map of the public transport in Brussels. I want to repeat the same circle for all the subway station. So, is it possible to make a clone of this circle. I want to modify all in the same time.

If I copy/paste, I have to change it individually. I don't want it.

Answer 1

You want symbols.
The basic instructions are to drag your artwork for the subway station to the symbols palette, and then drag it out of the palette or copy/paste it for all additional instances of the symbol. To edit all instances, just double-click the symbol.
For more info, see Adobe's page on symbols.