An ASA file is configuration file, created for ASP/ASP.NET projects. It contains declarations of variables, contains and functions that are meant to be accessible on Global level in the application. All the pages in the project can access these variables and functions, thus avoiding the requirement of rewriting these. One such example is the Global.asa page that is stored in the root directory to be accessible by other ASP website pages. Global.asa files are optional, but if used, each application can have only one Global.asa file.
ASA File Format - More Information
ASA files are plain text files with the following information.
the #include directive
ASA File Example
A Global.asa file could look something like this.
<script language="vbscript" runat="server">