Short answers, pulled from the story.
Luigi Bassi played the role of Don Giovanni in Mozart's opera in 1787. This performance featured him serenading a woman with a mandolin and cemented the instrument's image as an obscure tool of romance.
The three most common types of mandolin are the Neapolitan or round-backed mandolin, the archtop mandolin, and the flat-backed mandolin. The Neapolitan version has a deep bottom constructed from strips of wood glued into a bowl while the archtop features carved tops and shallower arched backs made from wood.
The standard tuning for the mandolin matches the violin at G3-D4-A4-E5 using four pairs of strings totaling eight strings. Other family members like the mandola tune a fifth below at C3-G3-D4-A4 and the octave mandolin tunes an octave below at G2-D3-A3-E4.
Significant composers who wrote music for the mandolin include Vivaldi, Beethoven, Mozart, and Gustav Mahler. Vivaldi created concertos including RV 425 in C major and RV 532 in G major while Beethoven composed four small pieces dating from 1796.
Electric mandolins were developed in the early 1930s contemporaneous with electric guitar development. Fender released a model in 1992 featuring an additional high A string above the E string plus tremolo bridge and extra humbucker pickup.