A need is something that is necessary for organisms to live a healthy life. Needs are distinguished from wants because a deficiency would cause a clear negative outcome, such as dysfunction or death. Needs can be objective and physical, such as food, or they can be subjective and psychological, such as the need for self-esteem. On a social level, needs are sometimes controversial. Understanding needs and wants is an issue in the fields of politics, social science, and philosophy.

To most psychologists, need is a psychological feature that arouses an organism to action toward a goal, giving purpose and direction to behavior.

The most widely known academic model of needs was proposed by psychologist Abraham Maslow. In his theory, he proposed that people have a hierarchy of psychological needs, which range from security to self-actualization. However, while this model is intuitively appealing, it has been difficult to operationalize it experimentally. It was further developed by Clayton Alderfer.

In text retrieval, full text search refers to techniques for searching a single computer-stored document or a collection in a full text database. Full text search is distinguished from searches based on metadata or on parts of the original texts represented in databases (such as titles, abstracts, selected sections or bibliographical references).

In a full text search, the search engine examines all of the words in every stored document as it tries to match search criteria (e.g., words supplied by a user). Full text searching techniques became common in online bibliographic databases in the 1990s^{[verification needed]}. Many web sites and application programs (such as word processing software) provide full-text search capabilities. Some web search engines such as AltaVista employ full text search techniques while others index only a portion of the web pages examined by its indexing system.

When dealing with a small number of documents it is possible for the full-text search engine to directly scan the contents of the documents with each query, a strategy called serial scanning. This is what some rudimentary tools, such as grep, do when searching.

Text may refer to:

Article may refer to: