消费者从kafka(经纪人)中提取数据.消费者指定要从其收集数据的位置开始的偏移量.如果Consumer断开连接并回来，它可以在离开的地方继续.它还可以从较早的位置开始使用数据(更改偏移量).

Consumer pulls the data from kafka (brokers). Consumer specifies the offset from where it wants to gather the data. If Consumer disconnects and comes back, it can continue where it left. It can also start consuming data from earlier point (changing the offset).