Disassembly
When referring to hardware, disassemble is the process of breaking down a device into separate parts. A device may be disassembled to help determine a problem, to replace a part, or to take the parts and use them in another device or to sell them individually. For example, if a computer has a bad processor a user may need to partially disassemble a computer to get to the bad processor and replace it.
When referring to software, disassembly is the process of getting the source code from a program.
Also see: Dissembler, Source