the meaning of decompiler
A decompiler is a computer program that translates an executable file to high-level source code. It does therefore the opposite of a typical compiler, which translates a high-level language to a low-level language. While disassemblers translate an executable into assembly language, decompilers go a step further and translate the code into a higher level language such as C or Java, requiring more sophisticated techniques. Decompilers are usually unable to perfectly reconstruct the original source code, thus will frequently produce obfuscated code. Nonetheless, they remain an important tool in the reverse engineering of computer software. Wikipedia