Filtering process is used to customize the data according to the users choice. It is a mechanism that includes or excludes specific data from reports based upon what the user decides to filter (e.g., to tightly tailor a report, you might strictly want records of customers between the ages of 25 and 35 who like skiing, but you want to exclude everyone else).
Data filtering is the process of choosing a smaller part of your data set and using that subset for viewing or analysis. Filtering is generally (but not always) temporary – the complete data set is kept, but only part of it is used for the calculation.
Filtering may be used to:
Look at results for a particular period of time.
Calculate results for particular groups of interest.
Exclude erroneous or “bad” observations from an analysis.
Train and validate statistical models.