GarageBand is a software application for Mac OS X and iOS that allows users to create music or podcast

Podcast

A podcast is a series of digital media files that are released episodically and often downloaded through web syndication...

s. It is developed by Apple Inc. as a part of the iLife

ILife

iLife is a suite of software applications developed by Apple for organizing, editing, and publishing photos, movies, and music. The suite comprises five applications: iPhoto, iMovie, iDVD, GarageBand, and iWeb, all of which run on the Mac OS X operating system....

 software package on Mac OS X.
GarageBand is a streamlined digital audio workstation

Digital audio workstation

A digital audio workstation is an electronic system designed solely or primarily for recording, editing and playing back digital audio. DAWs were originally tape-less, microprocessor-based systems such as the Synclavier and Fairlight CMI...

 (DAW) and music sequencer

Music sequencer

The music sequencer is a device or computer software to record, edit, play back the music, by handling note and performance information in several forms, typically :...

, which can record and play back multiple tracks of audio. Built-in audio filters allow the user to enhance the audio track for recording guitar instruments.