what is a hashtag? i reaaaally dont get it :(?

[Emily]

i know its stupid, but its also dumb.
now tell me what a hashtag is or means or what ever.
thanks k bye.
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[carmen]

It's a twitter thing. A hash tag is simply a way for people to search for tweets that have a common topic. For example, if you search on #LOST (or #Lost or #lost, because it's not case-sensitive), you'll get a list of tweets related to the TV show. What you won't get are tweets that say "I lost my wallet yesterday" because "lost" isn't preceded by the hash tag.

[David Clarke]

check the dictionary