A playlist is a custom compilation of songs and video. You might want to create a playlist to:
Suit a specific mood or occasion. For example, you could create a playlist for a dinner party, a wedding, or your morning workout.
Select certain songs to share with others on your local network or to sync with your iOS device.
Burn a CD of songs.
Organize your iTunes library.
There are five kinds of playlists; you create the first kind yourself and iTunes creates the other four for you.
Standard playlists: You create these playlists by dragging items to them.
Smart Playlists: Specify some rules for iTunes to follow, and it creates a Smart Playlist that updates automatically as your library changes.
Genius Shuffle: iTunes chooses a song, then plays songs that go great with it.
Genius playlists: Select a song in your library, and iTunes creates a Genius playlist of similar music in your library.
Genius Mixes: iTunes creates an ongoing playlist in a particular genre—like a commercial-free radio station—using the songs in your library.
With iPhone, iPad, and some iPod models, you can also create playlists (called on-the-go playlists) on the device when it isn’t connected to your computer. When you sync your device, your on-the-go playlists appear in your iTunes library. For information about on-the-go playlists, see the documentation that came with your device.