Dropbox is a cloud-based file storage and synchronization service that enables users to store, access, and share files and folders online. It offers features such as file synchronization across devices, file sharing with others, version history, offline access, security measures, and integrations with third-party apps. Dropbox is available in both free and paid plans, with premium options offering additional storage space and advanced collaboration tools. It is widely used by individuals, businesses, and teams for managing and collaborating on digital files and documents.