Hashtags seem like such a normal part of our culture that I almost didn't believe that they were first invented in 2007. It seems like there is a hashtag for everything from reality TV shows, to really important current events.
The purpose of a hashtag is to make information regarding a certain topic easily searchable for people on the internet. First used in 2007, the idea was proposed on Twitter, but it didn't catch on until a little bit later when the term #sandiegofire became wildly popular and hashtags began to be used heavily for everything over the next two years.
Many brands use their own hashtags on social media so consumers can easily find them and their products or services. This makes it easily accessible if a customer wants to see everything a company has to offer, including other people's experiences with the company.
Hashtags have even moved into areas like graduation classes using hashtags on platforms so recent grads can go through the tag and see photos from their graduation. The same concept is used for other events like weddings. The married couple can create a hashtag where guests can tag their wedding photos on Instagram so people can go through and see a collage of photos from the event.