This swing formation was founded by Chick Webb in the late 20s, from (and predating) the former Harlem Stoppers Webb's Quintet, and the Jungle Band.
During the early 30s, it was the Savoy Ballroom house band, and was dreaded as one of the Giants killer big band formation of the era (notably, the high-fly Goodman's orchestra was dwarfed during one of these Savoy "battles").
Integrating Ella Fitzgerald in its rank in 1935, the band enjoyed wide popularity and a few charts success, before Webb's dramatic death in 1939.
Ella Fitzgerald then lead the band for two more years under the name Ella Fitzgerald and Her Famous Orchestra, before going solo and splitting it up during the summer of 1941.
The band never really had stars in its rank (beside, of course, Ella Fitzgerald, and quick appearances of Benny Carter and Johnny Hodges) and its main strengths were its unity and Webb's amazing play.
A later Ella Fitzgerald release would "reunite" the former Webb Orchestra members during the 50s.
The band discography nowadays is available in two parts, the first (prior 1939) being detailed in Chick Webb's page, the second obviously found under Ella Fitzgerald and Her Famous Orchestra, which modern editions tend to scatter into Ella Fitzgerald discography (in the numerous releases covering the early Decca days).
The band was variously referred to as Chick Webb's Orchestra, Chick Webb and his Orchestra, Chick Webb's Band, Chick Webb and his Band, Chick Webb Savoy's Orchestra, etc.
There is absolutely no differences between these.