There are lots of resources for Hadoop and Big Data. There isn’t a conference I’ve gone to recently where someone didn’t raise their hand and asked: “What is Big Data?”
The top two glossary I use are Data Informed Glossary of Big Data terms here and the O’Reilly Book on this subject. For the more nerdy of you, another great resource is Google’s initial paper on MapReduce here
However, if you are looking for a quick reference slide on the basics as well as information on how big a terabyte is, you are most welcome to use the below!