Finsta is an abbreviation that stands for 'Fake Instagram.' It is a second Instagram account where someone can post things that they're too afraid to post on their main account. This account is often used to share more personal, unfiltered, or embarrassing content with a smaller, more trusted group of friends.
Finsta is a popular term among younger generations who use social media frequently. It is not as widely recognized or used among older generations or those who are less active on social media.