What does 'arco' mean for string instruments?

The term 'arco' specifically refers to the technique of playing string instruments with a bow. When a musician sees 'arco' in the sheet music, it instructs them to use the bow to produce sound on the instrument, as opposed to other techniques like 'pizzicato,' which indicates that they should pluck the strings. In performance, the bowing technique allows for a smoother and more sustained sound compared to the plucking of the strings, highlighting the expressive capabilities of string instruments. In this context, ‘arco’ signifies a fundamental aspect of string performance, emphasizing the use of the bow as essential for creating the desired tone and dynamics.