What is big data?
Put simply, 'big data' is data that exceeds the processing capacity of your existing database technologies.
What is Hadoop?
Apache Hadoop is an open-source software framework which allows you to cheaply store and process vast amounts of structured and unstructured data quickly, without investing huge sums of money.
How do big data and Hadoop fit together?
Hadoop and big data are synonymous. Most of the time when people are talking about big data they are actually talking about something which is running on Hadoop.