The symphony during Mozart's time centered around the 18th century while Beethoven's symphonies fit primarily into the 19th century.
Both periods used the four movement sonata-cycle for the formal structure of their symphonies, however the movements vary slightly. The first movement, a Sonata-Allegro in Allegro, and the second movement, a slow and lyrical Theme and Variations remain the same. The third movement is typically a Minuet and Trio in the 18th century while the 19th century composers preferred the livlier Scherzo and Trio. The fourth movement in the 18th century was usually a cheery Rondo conclusion while the 19th century saw the final movement as a dramatic and triumphant conclusion which tended to be just as grand in scope as the original movement typically in Sonata-Allegro form.
All information on this article is derived from:
Joseph Machlis and Kristine Forney. The Enjoyment of Music, Eight Edition, Standard Version, New York: W.W. Norton & Company, Inc., 1999.