If you include the right Instagram hashtags on your posts, you will likely see higher engagement than you would if you didn’t have any.
Because hashtags—a combination of letters, numbers, and emoji preceded by the # symbol (e.g. #NoFilter, #WorldCup)—categorize content and make it more discoverable. Anyone who clicks on a hashtag or searches for it will see a page with all the posts tagged with it.
— Leer en blog.hootsuite.com/instagram-hashtags/