英语连词前面的逗号有什么用?.,and.

英语连词前面的逗号有什么用?.,and.
举个例子：
1 Children will play with dolls equipped with personality chips,computers with in-built personalities will be regarded as workmates rather than tools,relaxation will be in front of smell-television,and digital age will have arrived.
2.In Europe,as elsewhere,multi-media groups have been increasingly successful:groups which bring together television,radio newspapers,magazines and publishing houses that work in relation to one another.
1.中的.......and digital 中的magazines and publishing 有什么区别？和区别的窍门？