Fugue is a contrapuntal compositional technique in which a short melody is introduced by one voice and then imitated by others, often at different pitches and with varying degrees of ornamentation. Fugues can be found in many different types of music, including classical, jazz, and folk.
Chase is a musical term that refers to a section of music in which two or more voices or instruments alternate playing the same melody, usually at different speeds. Chases are often found in Baroque music, particularly in concertos and sonatas.
So, while fugue and chase are both musical terms that involve the imitation of a melody, they are not the same thing. Fugues are more complex and involve more voices, while chases are simpler and usually involve only two voices.