Makes sense, broad means how many times those words are used in combination for all phrases in which contained them. Take "computer how to" for example. If you look at that broad there is a lot of searches, if you look at exact, a lot less. How many people do you actually think search for "computer how to". Now let's look at some other searches that contain these words.
How to fix your computer
how to build a computer
how to make your computer faster
The list can go on and on and on.
This is why you should never base your research on broad.
