<meta>
Metadata that no other element expresses: charset, viewport, description, Open Graph, robots directives.
Baseline: Widely available · Document structure
When to use it
charset first in head, viewport for responsive rendering, one unique description (~150–160 chars) per page.
When not to
Skip meta keywords (ignored since 2009) and only add robots when you need to restrict indexing.
Key attributes
charset- utf-8
name/content- description, viewport, robots…
property/content- Open Graph pairs
Example
<meta name='description' content='One compelling sentence describing this page.'>