Perl is an interpretter. Interpretters use languages in plaintext or a compiled form by reading instructions that go into another program, rather than compiled machine code, such as C, which is translated into the bytecodes of the processor. JAVA is an interesting situation, in that it is compiled bytecodes for a "virtual machine." Which is pretty much interpretting something that looks akin to machine code.

There is some validity to the idea that perl is compiled. It preparses the code into trees and and uses other methods which are a strong departure from the traditional idea of an interpretter.

Just Another Perl Backpacker