in the market ,on the market有什么区别啊?

in the market 意为在市场里（in 在这短语中指在某个空间里,无待 售之意）如：
1、He was foud stealing something in the market.（他在市场里偷东西时被人发现了.in the market强调地点）
2、NOw varieties of cheap computers are on the market for people to choose（如今,大量廉价电脑上市,有待人们挑选.）