Hash (noun): The # symbol on a keyboard or telephone.
Tag (noun): a label or identifying mark.
Hashtag (noun): a word or phrase starting with #, used to group relevant topics on the web.
A brief history of hashtags
- Originated in Internet chatrooms as a way to label conversation topics. #nerds
- Introduced to microblogging site Twitter in 2007. #billionairenerds
- Now used everywhere by everyone, including your mother. #weareallnerds