Hadoop is an open source, Java-based programming framework that supports the processing and storage of extremely large data sets in a distributed computing environment.
Hadoop is a distributed computing system that works on commodity hardware on a scale and speed that is just not possible for other database processing systems to match. Due to this there is a huge demand for Hadoop Developers who can deploy Hadoop on a massive scale.
Hadoop is a framework for distributed computation and storage of very large data sets on computer clusters. Hadoop has three core components are Hadoop Distributed File System (HDFS), MapReduce, Yet another Resource Negotiator (YARN).