Question

What is data mining? what kind of data the data mining is aplicable?

Answer 1

the practice of examining large pre-existing databases in order to generate new information is called data mining.
As a general technology, data mining can be applied to any kind of data as long as the data are meaningful for a target application. The most basic forms of data for mining applications are database data (Section 1.3.1), data warehouse data (Section 1.3.2), and transactional data (Section 1.3.3). The concepts and techniques presented in this book focus on such data. Data mining can also be applied to other forms of data (e.g., data streams, ordered/sequence data, graph or networked data, spatial data, text data, multimedia data, and the WWW).

Answer 2

Data mining is computing process of discovering patterns in large data sets for example the data mining step might multiple groups in the data.
There are two kind of data mining:
one can either try to predict or predict of class and some data.
I hope this answer is right