One reason that Jem is crying is because Nathan Radley lied to him about the tree being sick; Jem asked Atticus if it looked sick and he said it didn't, so this disappointment in a person's lies could be one cause of Jem's tears. More likely though, Jem is upset because their connection to Boo has been lost. They were just starting to form a bond, and Jem is realizing that Boo is lonely and reaching out for friendship. When that is taken away from him, it upsets Jem to the point where he starts crying.
Video games are sports that take place in a computer. They're interactive TV shows and interactive movies. They're digital board games and card games. They're rough simulations of everyday life including, probably, whatever you do for a living.
