说明：  我们用得最多的协议是UDP和TCP，UDP是不可靠传输服务，TCP是可靠传输服务。UDP就像点对点的数据传输一样，发送者把数据打包，包上有收信者的地址和其他必要信息，至于收信者能不能收到，UDP协议并不保证。而TCP协议就像(实际他们是一个层次的网络协议)是建立在UDP的基础上，加入了校验和重传等复杂的机制来保证数据可靠的传达到收信者。关于网络协议的具体内容，可以参考专门介绍网络协议的书籍，这里直接探讨编程实现网络程序的问题。
(We use the most agreement is UDP and TCP, UDP is not reliable transport services, TCP is a reliable transport service. UDP as point-to-point data transmission, the sender of data packing, has prepared to receive packets on the address and other necessary information for the receiver can not receive, UDP does not guarantee agreement. The TCP protocol is like (actually they are a level of network protocol) is built on the basis of UDP, joined the checksum ARQ complex mechanism to ensure that reliable data were communicated to the receiver. With regard to the specific content of network protocols, you can refer to specialized network protocols introduce the books, here to explore the direct network programming procedures.)