Google Business Profile is the free listing that represents your business on Google Maps and in the map pack at the top of local search results. It holds your name, address, phone number, hours, category, photos, services and reviews. For many local businesses it is seen more often than the website, and most calls and direction requests start there.
It used to be called Google My Business, and many people still say GMB. Anyone can suggest edits to it and Google will apply some of them without asking you, which is why an unclaimed or neglected profile drifts out of date on its own.
