Category: Disambiguation Information retrieval (IR) is the art and science of searching for information in documents, searching for documents themselves, searching for metadata which describe documents, or searching within databases, whether relational stand alone databases or hypertext networked databases such as the Internet or intranets, for text, sound, images or data. ... In computer science, a keyword is an identifier which indicates a specific command. ... In mathematics and computer science, Boolean algebras, or Boolean lattices, are algebraic structures which capture the essence of the logical operations AND, OR and NOT as well as the corresponding set theoretic operations intersection, union and complement. ... Originally, the word computing was synonymous with counting and calculating, and a science that deals with the original sense of computing mathematical calculations. ... A database is an organized collection of data. ... SQL(Structured Query Language) is the most popular computer language used to create, modify and retrieve data from relational database management systems. ... Opening (inverted) and closing question marks A question mark (or, less commonly, an interrogation point or eroteme) is a punctuation mark that replaces the period at the end of an interrogative sentence. ... Bang is: A loud noise, like an explosion (onomatopoetic). ... An exclamation mark (also exclamation point, and (rarely) mark of admiration) is a punctuation mark or, more pedantically, a tone mark. ... The Religious Society of Friends, commonly known as Quakers, or Friends, is a religious community founded in England in the 17th century. ... Quakers use the term Query to refer to question or series of questions used for reflection and in spiritual exercises. ...