1Password is a comprehensive password manager developed by AgileBits that secures passwords, passkeys, payment cards, secure notes, and sensitive documents through military-grade encryption. Unlike browser-based password managers, 1Password uses both a master password and a unique Secret Key for dual-layer encryption, ensuring that even a breach of 1Password's servers poses no threat to your vault data. The platform operates across unlimited devices with cloud synchronization, provides automated security monitoring through Watchtower, and offers specialized features like Travel Mode for border crossings, SSH key management for developers, and granular access controls for families and teams. Key to understanding 1Password is that your data is encrypted locally on your devices before transmission—1Password employees can never access your vault contents, making it a zero-knowledge security model that balances convenience with enterprise-grade protection.