Short answers, pulled from the story.
The word cello comes from the Italian violoncello, which means little violone. Violone translates to big viola and referred to large instruments in either the viol family or the violin family around the 17th century.
Andrea Amati created the earliest surviving cellos between 1538 and 1560 in Italy. Monteverdi called the direct ancestor the basso de viola da braccio in his opera Orfeo written in 1607.
Adrien Servais introduced the endpin in 1845 to provide greater stability compared to holding the instrument between calves. This innovation allowed cellists to support the instrument on the floor rather than between their knees.
Johann Sebastian Bach composed six unaccompanied Suites that remain among the best-known solo cello pieces today. Domenico Gabrielli treated the cello as a solo instrument earlier than most contemporaries around the late Baroque period.
Traditional cellos feature spruce tops paired with maple backs sides and necks though some use poplar or willow for back and sides. Hide glue allows reversible disassembly when repairs become necessary unlike regular wood glue which cannot be steamed open.