Anchor text is the visible, clickable text of a link. Search engines read it as a hint about the page it points to.
Why it matters
Descriptive anchor text helps people decide whether to click and helps search engines understand your pages. "Click here" says nothing; "our guide to cold brew ratios" says exactly what to expect.
Example
In an article about coffee subscriptions, linking the words "how to choose a grinder" to your grinder guide is far more useful than linking the word "here".
What to do
Write anchor text that describes the destination naturally. Don't force the exact same keyword into every link: varied, natural wording reads better and looks less manipulative.