How does fugato differ from a complete fugue?

A fugue is a complete musical composition or a self-contained section of a work characterized by the systematic imitation of a principal theme, known as the subject, across multiple melodic lines (counterpoint).12

In contrast, fugato refers to a passage of music that utilizes fugal style—typically an exposition—within a context that is not otherwise fugal. While a fugue is a formal, structured entity, fugato serves as a technique for thematic development within a larger, non-fugal movement. Essentially, fugato represents a "fugal" texture that lacks the full, rigorous development or the complete structural requirements of a formal fugue.34

Common examples of fugato can be found in the works of composers such as Wolfgang Amadeus Mozart and Ludwig van Beethoven, where they integrated these brief, imitative passages into symphonic movements to enhance thematic complexity.23