Your A–Z SEO glossary.

A 301 redirect is a permanent server-side instruction that sends visitors and search engines from one URL to another, passing along most of the original page's ranking signals.

Alt text (alternative text) is a written description added to an image's HTML code. It tells search engines what the image shows and gets read aloud by screen readers for visually impaired users.

Anchor text is the clickable, visible words in a hyperlink. Search engines use it as a signal about the topic and relevance of the page being linked to.