What it means
It is the panel that appears beside the search results when somebody looks up your business, and the pin that appears in Maps. You claim it, verify that you are really there, and then you control the hours, the photos, the services, the questions and the replies to reviews. It used to be called Google My Business.
Why it matters to a small business
For a business with a door, this is usually the single highest-return thing to fix, and it costs nothing. Most people searching for a local service never reach a website at all: they read the panel, look at the photos, check today's hours and tap call. A neglected profile loses those people before your site is ever in the running.
The bit people get wrong
Bank holiday hours are the one that actually costs money. Google keeps showing your normal Monday hours unless you set the special hours, so on the busiest Mondays of the year your listing tells people you are open when you are shut, or shut when you are open. Set them for the whole year in one sitting.
Source: Google Business Profile Help. This page is a plain-English summary written by the Marketeer team, not legal advice. Where money or the law is involved, read the source.