Using the DATA step is the primary method for creating a SAS data set with base SAS software. A DATA step is a group of SAS language statements that begin with a DATA statement and contains other programming statements that manipulate existing SAS data sets or create SAS data sets from raw data files.
You can use the DATA step for
creating SAS data sets (SAS data files or SAS data views)
creating SAS data sets from input files that contain raw data (external files)
creating new SAS data sets from existing ones by subsetting, merging, modifying, and updating existing SAS data sets
analyzing, manipulating, or presenting your data
computing the values for new variables
report writing, or writing files to disk or tape
A DATA step creates a SAS data set . This data set can be a SAS data file or a SAS data view. A SAS data file stores data values while a SAS data view stores instructions for retrieving and processing data. When you can use a SAS data view as a SAS data file, as is true in most cases, this documentation uses the broader term SAS data set.