A guitar tuner is a device used to adjust the pitch of a guitar's strings to ensure they are in tune. It detects the frequency of the sound produced by each string and indicates whether it is too high, too low, or in tune. Guitar tuners can be electronic, clip-on, or app-based, making them accessible for players of all skill levels. Using a guitar tuner helps musicians achieve the correct pitch, which is essential for harmonious playing. Proper tuning enhances the overall sound quality of the instrument and is crucial for performances, whether solo or with a band. Regular tuning is important for maintaining the condition of the guitar, as temperature and humidity can affect string tension.