media feature is the feature of a media that can be used in a media query in order to target the styling rule to a specific device.
Most media features accept optional ‘min-’ or ‘max-’ prefixes to express “greater or equal to” and “smaller or equal to” constraints in media_query
Example:
(max-width: 375px) and (min-resolution:192dpi)
You can find the detailed of each media feature in the specification
List the media feature of your user agent (generally your browser)
https://pieroxy.net/blog/pages/css-media-queries/test-features.html