Is box a free app?

Excuse me, I came across an app called "Box" and I was wondering if it's a free app or if there are any charges associated with using it? I'm always looking for ways to manage my files and collaborate with others efficiently, and Box seems like it could be a great tool for that. However, I'm on a tight budget and don't want to invest in an app that might not be worth it. Could you please clarify if Box is free or if there are any costs involved in using it? Thank you for your time.