Transitions are used is MANY things. In writing, transitions are placed into the form of words. These are called transition words. Some examples of transition words are: next, then, also, as a matter of fact, first, second, third etc... Trasitions are always used as a connected between things, so that everything makes sense. And it is important to cohesion because without them, sentences wouldn't make any sense, and would look something like this: "Marnie went to her back yard picked some roses went back inside ate dinner went to sleep dreamt a weird dream woke up." didn't make to much sense, did it?