Structured data is how you write that version deliberately instead of leaving it to inference.
What it actually is
A block of code on your page, invisible to visitors, that states plainly what the page is about in a format built for machines. That this is a business, its name, its address, its hours. That this is an article, published on a date, by a person. That this is a question and this is the answer to it.
None of it changes what a human sees. All of it changes what a system can say about you with confidence.
The distinction that matters is between inference and declaration. Without it, a system reads your page and guesses. Your phone number is probably a phone number. That paragraph is probably about pricing. Those hours probably apply to the location mentioned above. Usually the guess is right. Sometimes it is not, and you have no way of knowing which pages fell into the second category.
Everything about your business is already being interpreted. The only question is whether you wrote the interpretation or left a machine to assemble one from context.
Why it matters more now than it did
For years the argument for this was rich results: the star ratings and expandable answers that appear in search listings. That argument has weakened, since Google restricted several of those formats and the visual payoff is smaller than it was.
The argument that replaced it is larger. Systems that answer questions rather than returning links have to decide what they are confident about, and confidence is easier to reach from a declaration than from a paragraph. When an assistant states your hours, it prefers a source that said so explicitly over one where the information was probably in a sentence somewhere.
For a local business specifically, this is not a marginal advantage. Name, address, phone, hours, service area, and what you actually do, stated in machine readable form and matching what appears everywhere else, is one of the more direct inputs into whether you surface at all.
The three that cover almost everything
Most small businesses need three and no more.
Organization or LocalBusiness. Who you are, where, when you are open, how to reach you, what area you serve. This belongs on your home page and it is the one most businesses are missing entirely. If you have a physical location or a defined service area, use the local variant rather than the general one.
Article. On anything you publish. What it is, when it was published, who wrote it, and when it was last updated. That last field matters more than people expect, because a system deciding between two answers on the same subject weighs recency.
FAQPage. On pages built around questions and answers. One requirement worth stating: the schema must match the visible text. Marking up an answer that is not on the page is a violation rather than a shortcut, and it is detected.
A site publishes structured data across two hundred pages, each naming the business as publisher and pointing at the home page. The home page has no structured data at all. Every one of those references resolves to nothing. The individual pages are valid, the connection between them is not, and the business entity everything points at was never actually defined anywhere. That is a common failure and it produces no error message.
What to do with it
Write it once per page type rather than per page. Your article template carries the article block, your question pages carry the question block, and the values fill in from the content. Doing this by hand per page guarantees it drifts.
Then check it. Both Google and Schema.org publish free validators that will tell you whether your markup parses and what it declares. Paste in a page and read what comes back, because the output is the machine readable version of your business and it is worth seeing at least once.
The check nobody runs is whether the structured data still matches the page. Prices change, hours change, an article gets rewritten, and the block underneath keeps saying what it said originally. Structured data that contradicts the visible page is worse than none, because it teaches a system that your declarations are unreliable.
The honest limits
This does not make you rank. It makes you legible, which is a precondition rather than a cause. A business with immaculate markup and nothing worth saying will not outrank one with weaker markup and a genuinely better answer.
It also does not compensate for inconsistency elsewhere. If your hours are stated one way in your markup, another way in your listing, and a third way on your contact page, the declaration does not settle it. It adds a fourth source to a disagreement.
What it does is remove the guessing from the parts you actually control, at a cost of an afternoon and no ongoing spend. For a business competing against larger firms with more visibility, being the easiest one to describe accurately is not the whole game and it is a real advantage that most of your competitors have not bothered to take.