ASP.net and PHP are completely different. PHP is interpreted, meaning it never becomes a binary file to run, the interpreter interprets and runs what the script tells it to. ASP.net uses languages like VB or C# which get compiled into DLL's (binary files) and implimented. These files are already in code that the OS directly understands. ASP.net is a programming language that can easily be used on the web.

In case it still doesnt make sense, here is how each works
Scripting (PHP, ASP, ect): The commands you write are processed by the language processor at runtime and get interpreted to the machine commands as it goes. It never becomes an exe or dll or anything like that. Every time the script is called it re-interprets it (although cacheing can occur).

Programming (C#, C++, ect.): You write the code and put it though a compiler that breaks it down to machine code and leaves you with a ready to go binary file. That is it, the computer can simply run that because it is a binary.

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