How does a piano sonata differ from a violin sonata?

In the context of music, the primary difference between a piano sonata and a violin sonata lies in their instrumentation and the resulting structural roles of the instruments involved.

• Instrumentation: A piano sonata is typically a work for a solo piano, whereas a violin sonata is a work for violin accompanied by a keyboard instrument (historically basso continuo and later the piano).123
• Structural Evolution: Following the mid-18th century, both forms generally adopted the sonata pattern—a multi-movement structure often featuring sonata form in the first movement. However, while the string quartet typically includes a dance-derived third movement, piano trios and violin sonatas do not always follow this convention.12
• Keyboard Role: In earlier periods, the keyboard instrument functioned as an accompaniment using figured bass. By the late 18th century, as the harpsichord was superseded by the piano, the keyboard instrument became a dominant partner in chamber music combinations, including the violin sonata.3

While both are essential forms in the classical repertoire, they differ fundamentally in whether the keyboard acts as the sole protagonist or as a collaborative partner to the violin.23