Concept Search: A concept search attempts to match users with results that are the same concept or idea as their search, even if the results don't contain the word that was searched for.

Google and other search engines often employ this tactic as a form of vertical search results. In other words, the search engine might understand that one phrase is related to another and return results for one or both ideas. They may draw on a user's prior search history, or they may gather this information from all users' searches for a particular topic. By gathering these results, search engines are able to predict the intent of the user's search.

An example of this can be seen when a very general search is performed on Google. When searching for a term like "comedy films," Google not only displays results related to the genre of comedy, but it also shows a banner filled with "Movies frequently mentioned on the web." Even if a user didn't search specifically for films such as Anchorman or Monty Python and the Holy Grail, the results show up in Google as suggestions based on the searches and web traffic of others.

Another platform that uses the concept search is Netflix. If a user rated certain films highly or recently finished watching a TV series, Netflix attempts to guess what the user may want to watch next. Shopping websites, like Amazon or eBay, may also draw from a user's previous searches and viewed items to display results that may lead to a purchase.