What is a ghetto?, Where were they stablished?

A young man threw himself from a thrid floor down in the Warsaw ghetto,but for he had not eaten since the past week. Another woman killed herself with one shaving blade because she had no medicine left for her disease...
These and more were some of the unbearable conditions that many Jews suffered prior to the sickening concentration and extermination camps that awaited them not too far from their current homes. Jews had been confined ever since Renaissance when they were sent to the worst parts of Venice. Later they began to gain power and money, and they soon became powerful, wealthy and educated. World War II began, and Adolf Hitler confined again the Jews in filthy and smallparts of the city wher he and his comrades embargoed food, medicines, and other basic supplies. The ghettos served as the antechamber of concentration and extermination camps not only for Jews but also for Gypsies. The ghettos for Jews were oftne called Kibuks.
Mr. Crow: I feel so awful when talking about confinement, concentrationes, and all this stuff; however, it is needed. The main ghettos during World War II were Lakhva,Belarus; Ghetto Litsmannstadt(second largest after Warsaw ghetto), German Poland; Lemberg ghetto, Ukraine; Krakow ghetto, Poland; Budapest, Hungary; Kaunas ghetto, Germany; Vilna ghetto, Lithuania; and most importantly the Warsaw ghetto which was the largest ghetto during World War II. The ghettos I mentioned are far less than the existent. If you want to know more about them, look at the image. I think there are over 50.