How do people catch diseases like chickenpox from others if it is contracted through close contact...?

and the person who has it dosent look sick?Wouldnt the person who gave it to you look sick , so how do people get it then?

The problem is that people often don't recognize that they are sick in the early stages of illness, and that's the time when they are the most contagious. A lot of diseases, you've infected people for a week, before you know you're sick.Or like Herpes, which is in the same family as Chicken Pox; people who carry the Herpes virus have zero symptoms between flare-ups, and yet they are always contagious.