In web search or document retreival, the search terms are the words you enter into a form as a query. Unlike a structured database query with fixed fields, the terms may usually occur anywhere on the text of the web page or document, requiring special foms of free text index. This may include dealing with stemming, mistypings or even terms with similar semantic meanings to the search terms.
Sometimes it is possible to link search terms in semi-structured ways, for example, adding logical connectives such as "food AND ( dog OR cat)". The search results are often ranked in terms of relevance based on how many or frequently the search terms appear in the retrieved documents and how common the terms are, for example in the search terms "an aunt antidisestablishmentarianism", 'an' would be weighted less than 'aunt' and both less than 'antidisestablishmentarianism'.