Big Data Analysis is analysis of data, but here data is not just your usual data - numbers, strings etc. In fact, it is data which is huge in size(volume), variety, and generated at high velocity and this data may be structured and/or unstructured.
Your traditional data processing tools can't handle such data, you have different architecture as well as algorithms to not only process such data but also to store.
Hadoop is popular framework used for the same.
I am assuming you know about analysis.