Pantaloon (Signor Pantalone): a miser
Isabella (Inamorata): his daughter
'Oratzio (Inamorato): her lover
Harlequinn ('Arlecchino, a zany): servant of Pantalone
Columbine: maid servant of Isabella
The Doctor (Il Dotore): a charlatan (the bird nosed mask of the plague doctor is one of the most frightening images of the art of that time. It was constructed to allow nostrums to be stuffed into the nose of the mask, as this was thought to protect against plague. So, if you looked up and saw this mask hovering above you, it meant you had the plague...)
The Captain (Il Capitano): an aquaintance of Pantalone, and a suitor for the hand of Isabella.
Troupes of Italian actors traveled the continent during the late 1600's and 1700's performing pieces with set characters and improvised dialog reflecting local characters and local scandals. The natural excitability and overly exuberant theatrical delivery common to Italians was much appreciated all across Europe, particularly in Germany where they love nothing better than a good fart joke. Music and dance, as well as juggling and other bits of 'funny business' were an important part of each performance. Naturally they were much frowned upon by the church and authorities, but the common folk loved them with a passion that is still widely reflected today.
So, who's got the next question?