说明：  一个分布式系统基础架构，由Apache基金会开发。用户可以在不了解分布式底层细节的情况下，开发分布式程序。充分利用集群的威力高速运算和存储。Hadoop实现了一个分布式文件系统（Hadoop Distributed File System），简称HDFS。
(A distributed system infrastructure development by the Apache Foundation. Users can not understand the underlying details of the distributed case, the development of distributed applications. Take full advantage of the power of cluster computing and high-speed storage. Hadoop implements a distributed file system (Hadoop Distributed File System), referred to HDFS.)