Definition
In web development, markup refers to the use of tags and syntax (primarily HTML) to define the structure and presentation of content in a document. HTML (HyperText Markup Language) is the foundational markup language of the web. In a business context, markup also refers to the percentage added to the cost of a product or service to determine its selling price. For creators building websites or writing blog content, understanding basic HTML markup enables better control over formatting, SEO metadata, and content structure.