Big Data is not just about velocity, volume, veracity and variety. It is about how you identify the right information from data that is growing exponentially, and use it to add business value.
Hadoop
Apache Hadoop is an open source project that offers a new way to store and process big data. Hadoop is a framework for storing, analysing and accessing large amount of data, quickly and cost effectively through clusters of commodity hardware. Web 2.0 companies such as Google and Facebook use Hadoop to store and manage their huge data sets.
Hadoop is capable of computing on single server to thousands of machines and provides a low cost, but then dependable solution to tackle data management problems.
Hadoop ecosystem includes: Hadoop, MapReduce, HDFS, HBase, Zookeeper, Hive, Pig, Sqoop, Cassandra, Oozie, Flume, Spark.