Obsidian is compatible with multiple platforms including Windows, macOS, Linux, Android, and iOS. This cross-platform support enables users to access their notes and projects from almost any device. Data synchronization across devices can be achieved using third-party cloud services.

Yes, Obsidian offers a free version that provides a comprehensive set of features suitable for most users. It allows unlimited vault creation, use of community plugins, and access to core functionalities like backlinks and graph views. More advanced features and priority support are available through paid plans intended for more demanding users.

Obsidian prioritizes data security and privacy by storing all data locally on the user's device by default, giving users full control over their information. It does not require an account for use, ensuring data privacy. For cross-device synchronization, users can select and connect to their preferred third-party cloud services.

While Obsidian is primarily designed for personal knowledge management, it is not built for real-time collaboration like some other note-taking apps. Users can share vaults via cloud services or utilize plugins to facilitate collaboration. For team collaboration, integration with additional tools may be necessary.

Obsidian distinguishes itself by its unique approach that emphasizes linking and connecting notes in a non-linear way, allowing users to create a personal knowledge graph. This system makes discovering connections between ideas easier. Its flexibility, extensive plugin support, and community-driven development further set it apart from traditional note-taking applications.