SAP script is SAP's text processing system used to print preformatted text in forms. It allows alignment of text, use of different fonts, and printing of company logos. A layout set defines the page design and formatting for a document through windows, paragraphs, and character formats. A print program selects data from a database table and feeds it to the layout set to print the document. Functions like new page, include, address, perform, if/else, and protect can be used in SAP script programs.