A Personal Digital Assistant, or PDA, is a handheld device designed to help users manage personal information. It typically includes features like a calendar, address book, task manager, and note-taking capabilities. PDAs were popular in the late 1990s and early 2000s, often used for organizing schedules and contacts. 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 While they have largely been replaced by smartphones, which combine PDA functions with phone capabilities, the concept of a portable digital organizer remains influential in today's technology.