1. There are two types of libraries in SAS: Work and Permanent.
  2. The Work library contains temporary data sets. The data sets are deleted when the current SAS session ends.
  3. The Permanent library contains permanent data sets. When referencing a permanent data set in the code, you must use a library reference (libref).
  4. A permanent library can be created by using a LIBNAME statement. You can save a current SAS data set by simply copying the data into the permanent library using a SET statement.