Virtual instruments are software applications that simulate traditional musical instruments, allowing users to create and manipulate sounds on a computer. They can replicate the sounds of instruments like pianos, guitars, and drums, providing musicians with a wide range of options without needing physical instruments. These tools are often used in music production, film scoring, and live performances. Many virtual instruments come with built-in features such as MIDI compatibility, which allows users to control them using a MIDI keyboard or other devices. They can also include various effects and sound manipulation options, making it easier for composers and producers to experiment with different sounds and styles.