Pseudocode
lastmod 2015-03-12created 2015-03-121 edits
Pseudocode is code that describes an algorithm by imitating code in ordinary language, rather than following the syntax of a specific programming language. Since pseudocode, as the name says, only imitates code, it cannot be run on a computer like code written in a real programming language; it is used to roughly model an algorithm before writing a program in a specific language.
Because pseudocode does not need to follow strict syntax like a real programming language, many variants exist. However, it often mimics the syntax of widely used programming languages such as C, Lisp, or Fortran. Natural language is also used freely where a rigorous description is unnecessary.
Computer science textbooks especially use a lot of pseudocode in their explanations so that speakers of various languages can all understand them. Also, since pseudocode syntax usually differs from author to author, the syntax of the pseudocode is sometimes briefly explained at the beginning of a book.