Markup

Markup: presentational, structural, semantic

Markup is made up of a set of symbols or language that are used to provide instructions to a webpage on how that page should look and work - like how HTML marks up content in order to format text, images in a webpage. Presentational markup is used to achieve a visual effect. Structural markup is when elements like title, headings, tables, lists etc are used. Semantic markup involves using elements that have to do with content meaning and allows content to be shared.