A looper pedal is a versatile tool used by guitarists to record and playback musical phrases in real-time. It allows musicians to layer multiple parts, create loops, and build entire arrangements on the fly. Looper pedals come in various configurations and offer different features, but they typically include the following functionalities:

1. **Recording**: A looper pedal enables users to record a musical phrase by pressing a dedicated footswitch. Once the recording is initiated, the pedal captures the incoming audio signal from the guitar or other instrument and loops it back continuously.

2. **Playback**: After recording a loop, the looper pedal plays back the recorded audio continuously in a seamless loop. This allows musicians to accompany themselves or create layered arrangements by adding additional musical parts on top of the original loop.

3. **Overdubbing**: In addition to recording and playing back loops, looper pedals often feature overdubbing functionality, which allows users to layer additional recordings on top of existing loops. Musicians can continuously add new musical parts to the loop, building up complex arrangements in real-time.

4. **Undo/Redo**: Many looper pedals include an undo/redo function, which allows users to remove the last recorded overdub or restore it if needed. This feature provides flexibility and allows for experimentation during live performances or recording sessions.

5. **Stop/Clear**: Looper pedals typically include a stop/clear footswitch that allows users to stop playback and clear the recorded loop from memory. This enables musicians to start fresh with a new recording or transition to a different musical section during a performance.

6. **Loop Length Control**: Some advanced looper pedals offer the ability to control the length of the recorded loop. Users can specify the length of the loop in measures or seconds, allowing for precise control over the timing and structure of the looped arrangement.

7. **Built-in Effects**: Some looper pedals feature built-in effects such as reverse playback, half-speed playback, or pitch shifting, which can add creative possibilities and sonic experimentation to the looping process.

Looper pedals are widely used by guitarists and other musicians for various applications, including live performance, songwriting, practice sessions, and studio recording. They provide a convenient and intuitive way to create, layer, and manipulate musical ideas in real-time, making them an essential tool for creative expression and musical exploration.