If you spend much time on social media, you’ve probably heard of Throwback Thursday and Flashback Friday. Social media users can post an image, video, or song from the past and tag the post with #ThrowbackThursday or #FlashbackFriday, depending on the day of the week.

You can probably figure out the meaning from the hashtag itself, but why two? What’s the difference between Throwback Thursday and Flashback Friday?

According to Google Trends data, #FlashbackFriday has been around longer than #ThrowbackThursday. However, the latter seems to be more popular these days. Both trends started in 2013. Throwback Thursday may be more popular because it is a more active time for social media in general.

The definitions of throwback and flashback may differ slightly, but the point is the alliteration. Both hashtags are used to reflect on past memories, movies, songs, shows, products, events, or trends. Content shared for each hashtag is nearly indistinguishable.