Syncing music allows you to copy music from your computer to a portable music device like an iPod or a Zune. You need to have software that allows you to transfer the music on your computer to your specific portable music device.
Etymology of Sync
Sync is a shortened form of the word synchronization which means "to happen at the same time." The word sync (not synchronization) first appeared in 1961 referring to making the video and audio of a movie occur at the same time.
Using iTunes to Sync Music
In order to sync an iPod, you will need iTunes (which you can download for free from Apple's website). Once your iPod is connected to your computer, it will automatically sync its contents with the computer. By choosing a playlist, then clicking your iPod's name from the menu on the left of iTunes, you will be given the chance to sync the selected music to your iPod.
Using WMP to Sync Music
MP3 players can be synced using Windows Media Player (WMP). To sync music in WMP, attach your MP3 player to your computer and click the "sync" tab on the top menu of the program. Drag the music you want to put on your MP3 player to the sync list on the right of the screen and then click "start sync"