Acoustic Guitar, Classical Guitar and Folk Guitar differ in the following three aspects:

1. Appearance and design: Acoustic Guitar usually refers to the sound box amplification that relies on the instrument itself The guitar, whose strings vibrate waves to produce sound, has a beautiful and elegant shape. Classical Guitar is a guitar specially designed for playing classical guitar repertoire. It has a simple and elegant style, and uses non-metallic strings. Usually its sound box is slightly larger than that of folk guitars, with mellow sound quality and more accurate response to mid-bass. Folk Guitar is characterized by the use of steel strings, with a clear and loud sound. It is suitable for off-site performance, so it often comes with a shoulder strap.

2. Playing style and purpose: Classical Guitar is the most artistic form of guitar playing. It is also known as the world's three major classical instruments together with piano and violin. It usually appears in the form of solo or duet, usually in the form of solo or duet. It mainly plays traditional classical music, which is widely popular around the world. Folk guitar was originally an accompaniment instrument for American western country music. It usually appears as an accompaniment to songs, with American western country music as the main performance theme.

3. Tone and sound quality: The pronunciation quality of Acoustic Guitar is usually the best. Classical Guitar's sound quality is mellow and its response to mid-bass is more accurate. The sound of Folk Guitar is clear and loud, making it suitable for off-site performance.

In summary, these three guitars are suitable for different occasions and music types. Which one to choose depends on your specific needs and preferences.