A Google Business Profile, formerly known as Google My Business, is a free business listing from Google. If you use Google at all, then you'll have probably seen one before. They look something like this:
As far as SEO goes (How high up you appear in search results), this is just about the most important thing you can do as a local business.
Creating a Google My Business profile is the modern day equivalent of entering your business into the yellow pages, but better.
In the yellow pages, your business will appear somewhere between your competition with no way of showing up more frequently or on the first page.
However, with Google Business Profile, we can 'out-rank' our competition, meaning that our Business profile will appear at the top for most of our industry keywords.
I.e. if you're a plumber, with some smart optimisation, you could get your business profile to appear every time someone locally searches for plumber or leaking tap etc.
The catch to this, however, is that you need to have a business address. If you're an online business only, this is not an option for you.