So, you have a leak under the boiler, time to find a plumber.
In years past, you would have reached for the yellow pages, found a suitable company, and made the call. Now though, Google is probably your first port of call. So you search for "Plumber".
These days Google probably knows where you are, but only a few years ago, this would have led to a huge list of Plumbers around the world. The top result would have been for a company in Ohio, and while they would be able to do the work for you, the call-out charge would have been ridiculous...
So the next step is to give some sort of locality, by changing the search to "Plumber Ashford". (As a Web-Guru I would search for "Plumber 01233" so that I found plumbers from the correct Ashford, with a landline number listed.)
What we have done is cut the pile of plumbers down from all of those in the world, to those which we are interested in.
After calling a few, you realise that not all plumbers deal with boilers, so you change your search again to "Boiler repairs Ashford".
The morale of this story is two-fold. First you need to consider what people will search for when they are looking for you, and second, the longer the chain of words used in the search, the more likely you are to be able to appear for those words.
Trying to compete with the other 100 million Plumbers (or Insurance People) in the world is going to be really hard, so adding locality or specialisation will help you appear when the searcher is trying to find you specifically.