iTunes was a media player and media library application developed by Apple Inc. It was used for playing, downloading, and organizing digital multimedia files, including music and video, on personal computers running the macOS and Windows operating systems. iTunes also served as a platform for purchasing, downloading, and managing digital music and videos.

Key features of iTunes included:

1. Music and Video Playback: Users could play digital media files, including music and videos, with support for various file formats.

2. Media Library Organization: iTunes provided tools for organizing and managing large collections of music and videos, including the ability to create playlists, categorize media, and create custom libraries.

3. iTunes Store: This was an online store where users could purchase and download digital music, music videos, television shows, movies, audiobooks, and podcasts.

4. Device Synchronization: iTunes allowed users to sync their media libraries with their iPods, iPhones, iPads, and other Apple devices, enabling the transfer of music, videos, and other media content.

5. Backup and Restore: Users could back up their iOS devices and restore them using iTunes, enabling the restoration of devices to a previous state if necessary.

However, in recent years, Apple transitioned away from iTunes and introduced separate apps for specific functions, such as Apple Music for music streaming, Apple TV for video content, and Finder (on macOS) for device management and synchronization. This transition aimed to streamline the user experience and make it easier to manage different types of media and devices separately.