Big data analytics as name suggests deals with complex relational and non relational data bases with different data structures. Analyzing them (not essentially through charts) through analytics such as correlations, forecasts clustering etc is big data analytics. Some of the tools are apache spark, hadoop, hive etc.

Visual data analytics on the other hand doesn't have to be big data and involves performing descriptive and exploratory analysis through visualizations. Some of the tools are BI tools like Tableau, power BI, cognos

Here is a good paper

http://kops.uni-konstanz.de/bitstream/handle/123456789/22540/Zhang_225405.pdf?sequence=2

Thank You Dear Nagdev Amruthnath , for your inputs

Bigdata analytics handle huge data that is not possible in conventional way. Visualisation allows you to have a grasps of output of analysis visually.

Thank You Dear Ajit kumar Roy but again I have one query i context with your reply.

Ajit kumar Roy Nagdev Amruthnath

In which condition, we can refer anything as Data, when data become data-set and same data-set get form of very large data-set?

is there any specific value or range where we can refer it as Data or dataset or large data set?