BlackBerry OS is a mobile operating system developed by BlackBerry Limited for its smartphones. Launched in 1999, it was designed primarily for business users, offering features like secure email, messaging, and calendar functions. The OS was known for its physical keyboards and robust security, making it popular among corporate clients. Over the years, BlackBerry OS evolved to include touch-screen capabilities and a more user-friendly interface. However, with the rise of competitors like iOS and Android, its market share declined. In 2016, BlackBerry Limited announced it would stop developing its own OS, transitioning to a software-focused business model.