Q:

What is the Difference between PHP and ASP?

ASP is a Compiled Language or isnt it? sure it is.
PHP is a Interpreted Language. 
I also developed once an asp app with the VS 2008 IDE.
But there is a Big difference between ASP and PHP. 
What are the Differences? 

A:

ASP is a Compiled Language or isnt it? sure it is.

No, it isn't.
The first reason why ASP is not a compiled language is because there is no such thing as a compiled language. A language is neither compiled nor interpreted. A language just is. A language is a bunch of abstract mathematical rules. Interpretation or Compilation are traits of a language implementation, they have nothing to do with the language. Every language can be implemented by either a compiler or an interpreter; most modern high-performance language implementations actually use both and switch between them depending on which one is faster in a particular context.
The second reason why ASP is not a compiled language is because it is not a language. It is a framework. You can write code for ASP in any language for which an ActiveScripting engine exists (e.g. Ruby via ActiveRuby), but most commonly one would write code in either VBScript or JScript.
Which brings us to the third reason: The implementations of VBScript and JScript that ship with Windows, as well as ActiveRuby and all other ActiveScripting engines that I know of, are pure interpreters, they cannot compile. So, even though I wrote above that any language can be implemented using either a compiler or an interpreter, all the language execution engines that are supported by ASP are interpreted.

PHP is a Interpreted Language.

Again: no, it isn't.
Reason one is the same as above: there simply is no such thing as an interpreted language.
And, in contrast to ASP, the vast majority of PHP implementations actually do contain a compiler. Some even are pure compilers, they don't even have an interpreter. (Phalanger, for example always compiles straight to CIL, with no interpretation whatsoever. P8 can either interpret or compile straight to JVM bytecode or both: interpret, gather profile data while interpreting and then JIT-compile to JVM bytecode.)

But there is a Big difference between ASP and PHP. What are the Differences?

ASP is a (language-independent) framework, PHP is a language. That's a rather big difference. (Actually, PHP contains one small bit that would in other languages usually considered to be part of a web framework: webserver integration.)
PHP is highly portable across operating systems, CPU architectures and webservers: there is a PHP implementation for nearly every execution environment, from the JVM to the CLI to Parrot to running natively on pretty much every operating system under the sun. ASP is pretty tightly bound to Microsoft Internet Information Server, Microsoft Windows and the PC platform. (There were some other implementations but they are pretty obscure and no longer available.)
PHP has lots of different implementations (Phalanger, Quercus, Pipp, PHC, P8, Zend), ASP has only one. (Like I said, the two other ones are no longer available.)
The vast majority of PHP implementations are Open Source (I think the only exception is P8), while all three ASP implementations that I know of are proprietary.
PHP is actively developed and maintained, whereas ASP is largely obsolete and has been superseded by ASP.NET.

A:

You could be more specific with your question. 
The biggest difference is of course that ASP is programmed in a .NET language and uses the .NET framework as a basis. PHP of course is programmed in PHP and with it's library.
.NET is compiled into bytecode and that bytecode is interpretted/jitted at runtime. There are also bytecode caches for PHP (e.g. APC) and there is an active project that aims to generate native code from it using LLVM.

