The second word ( libref) is what you name the library.
Here the first word ( LIBNAME) is the SAS keyword that tells it to create a library. The format of the LIBNAME statement is: LIBNAME libref 'Folder path name here' A LIBNAME statement is one of those global statements that we mentioned in Section 1 that does not occur in a data step or a proc step. A library is assigned a location with a LIBNAME statement in SAS. One or many datasets can be assigned to the same library. Alternatively, you can create your own data in SAS, which is also covered below. If it is stored as a file other than SAS (Excel, SPSS, text, etc.) then you’ll need to help SAS read it with one of the methods described in the next sections of this tutorial. If the data you want to work with is already a SAS dataset stored somewhere on your computer, then all you need to do to start working with your data is assign a library name to the location of the dataset.
SAS libraries allow users to safely store things like data sets and user-defined formats so that they can be accessed without having to reload or re-read them from an external file every time SAS is started. A SAS library is a folder located on a user's disk drive or on the internet that is specially designated for use by SAS.