What is asp basic syntax rule?

An ASP file normally contains HTML tags, just like an HTML file. However, an ASP file can also contain server scripts, surrounded by the delimiters . Server scripts are executed on the server, and can contain any expressions, statements, procedures, or operators valid for the scripting language you prefer to use.

What are session variables?

Session variables are used to store information about ONE single user, and are available to all pages in one application. Typically information stored in session variables are name, id, and preferences.
Tell about application variables.
Application variables are also available to all pages in one application. Application variables are used to store information about ALL users in a specific application.