"Source code" is a generic term in computer software which refers to the instructions written by a human for a computer to follow; also called a computer program or script.

In the context of web publishing, document source refers to the plain text containing the instructions used by a Web Browser to produce a formatted document or fill-out form. Source for a web page may be viewed using a graphical browser with the "Document Source" or "View Source" menu option, or using lynx with the backward slash "\".