How does counterpoint differ from polyphony in Western music?

It is a common misconception that the terms "counterpoint" and "polyphony" are synonymous; however, they refer to distinct aspects of music.

Polyphony is a broad term describing music that consists of two or more distinct melodic lines sounding simultaneously. In contrast, counterpoint refers specifically to the compositional technique used to handle and combine those melodic lines.12

The relationship between the two can be summarized as follows:

• Polyphony as Texture: Polyphony describes the resulting musical texture where multiple voices are perceived as independent yet related. It is the overarching characteristic that distinguishes Western art music from many other musical traditions.2
• Counterpoint as Technique: Counterpoint is the craft of managing these lines. Effective counterpoint balances two dimensions: the "horizontal" (the independence and individuality of each melody) and the "vertical" (the harmony created by the relationship between the notes).1

While polyphony defines the presence of multiple voices, counterpoint provides the rules and artistic methods for how those voices interact.12