Hashtag vs. Metadata — What's the Difference?

A hashtag is a metadata tag that is prefaced by the hash symbol, #. Hashtags are used on microblogging and photo-sharing services such as Twitter, Instagram and WeChat as a form of user-generated tagging that enables cross-referencing of content; that is, sharing a topic or theme.

Metadata is "data that provides information about other data". In other words, it is "data about data".

A searchable keyword or sequence of characters prefixed with the pound sign (#), included in a tweet or other electronic communication and indicating the subject matter.

Data that describes other data, serving as an informative label.

(Internet) A metadata tag, signaled by a preceding hash sign (#), used to label content.

(computing) Structured information about a file (date created, creator, software used to create, last modified, file format, file fingerprint, etc).

The hash sign itself, when used as part of a hashtag.

Data about data;

To label (a message) with a hashtag.