Data Mining is the process of identifying trends in large data sets.
Steps are as following:

1. Business understanding
2. Data understanding
3. Data preparation
4. Modeling
5. Evaluation
6. Deployment

The data is usually collected and stored in data warehouses.
Then we apply suitable data mining algorithms for identifying trends.
Most popular algorithms are clustering and regression trees.

Data Mining can be done for:

1. Mining for patterns
2. Mining for associations
3. Mining for correlations
4. Mining for clusters
5. Mining for predictive analysis