In simple word SAS is a business analytics software which is used to process and analyze data in may different ways,
SAS (pronounced "sass") once stood for "statistical analysis system," and began at North Carolina State University as a project to analyze agricultural research. As demand for such software grew, SAS was founded in 1976 to help all sorts of customers - from pharmaceutical companies and banks to academic and governmental entities. SAS – both the software and company – thrived throughout the next few decades. Development of the software attained new heights in the industry by being able to run across all platforms, using the multivendor architecture for which it is known today. While the scope of the company spread across the globe, the encouraging and innovative corporate culture remained the same.
From SAS official website
Base SAS is the core of SAS and it contains basics procedures and data management.In Base SAS module you will learn Introduction to SAS Interface, reading data using datalines, formatting, SAS Functions, loops and arrays and much more .