HDFS is an Apache Software Foundation project. a subproject of the  Apache Hadoop project. Hadoop is ideal for storing large amounts of  data. like terabytes and petabytes uses HDFS as its storage system. HDFS  nodes contained within clusters over data files distributed. then  access and store the data files as one seamless file system. Access to  data files handles in a streaming manner. that applications or commands  execute the MapReduce processing model.
HDFS is high-throughput access to large data sets. the primary features of HDFS provide a high-level view.
HDFS has many similarities with other distributed file systems. but is different in several respects. One noticeable difference is HDFS's write-once-read-many model. that relaxes control requirements, simplifies data, and enables high-throughput access.
The attribute of HDFS is viewpoint data rather than moving the data to the application space. 
HDFS restricts data writing to one writer at a time. Bytes are always appended to the end of a stream. the byte streams to store in the order written. 
HDFS has many goals. Here are some of the most notable 
  Fault tolerance by detecting and applying quick automatic recovery
  Data access via MapReduce streaming
  Simple and robust model
 the data close to the processing logic
  Portability across commodity hardware and operating systems
  Scalability to store and process large amounts of data
  Economy by distributing data and processing across clusters of commodity personal computers
  Efficiency by distributing data and process it in parallel nodes data.
  many copies of data and redeploying processing logic in the event of failures 
HDFS provides interfaces for applications to move them closer to data located 
 
