What is a keyword (in SEO and Google Ads)?

In SEO, a keyword is the phrase you want a page to be found for. One marketing agency's guide describes it as the phrase a person enters into a search engine, and the phrase a page is deliberately built to answer². If you sell trail shoes, "trail running shoes" might be one.

You pick it by asking what your buyer would type. Then you write a page that answers that question well. The aim is a useful page. Repeating the phrase does not help.

In Google Ads, a keyword is a word or phrase describing what you sell, chosen to help decide when and where your ad can appear¹. Google says an ad can become eligible based on how similar your keywords are to the person's search terms, and on your match types¹. You are placing a bet: "show my ad to people who search something like this."

How closely a search must resemble the keyword is set by match types. Words you do not want to trigger an ad are blocked with negative keywords.

No. The keyword is what you chose. The search term is what the person actually typed. They can differ a lot, which is why reports list search terms separately. Our convention: say "keyword" for your choice and "search term" or "query" for theirs.

The reason behind a search is its search intent. Two people can type the same words and want different things.

Clicks are not buyers. A keyword that brings many visits and no orders costs money. A keyword that brings few visits and many orders earns it. And some phrases would find you without any ad at all.

That last point is a question of incrementality: whether the ad added the sale, or the person would have found you anyway.

Some campaign types work differently. Performance Max is a Google Ads campaign type that reaches all of Google's inventory from one campaign, with Google's AI managing bids, budget and placements. For the wider search picture, see AEO vs GEO vs SEO.