Personal Digital Assistants (PDAs) are handheld devices designed to help users manage their personal information. They typically include features like calendars, address books, to-do lists, and note-taking capabilities. PDAs were popular in the late 1990s and early 2000s, often used for organizing tasks and scheduling appointments. Many PDAs also offered connectivity options, allowing users to sync data with computers or access the internet. While they have largely been replaced by smartphones, which combine PDA functions with phone capabilities, PDAs played a significant role in the evolution of mobile technology and personal organization tools.