Index (Database)
The distributed database holding a compressed record of every page the engine has decided to keep.
Analogy Mental model
The stacks, the card cabinet and the digital catalogue, all describing one collection. You can browse the shelves, but the cabinet is what makes the collection usable.
In practice What you actually do
Use site: queries as a trend line rather than a census. Run site:example.com monthly and watch the shape. A sudden collapse usually means a robots directive, a canonical mistake or a manual action, and it shows up here days before it shows up in your traffic charts.
Where people get burned Pitfalls
A hundred thousand product pages with five thousand indexed URLs is not a reporting quirk, it is a structural failure. Crawl budget, faceted navigation and duplicated templates are the usual suspects, in that order.
This entry was written in English from the Chinese original, not machine-translated. Read the Chinese version →