A compiler is a software program that is used to translate high-level text based source code written in a computer language (e.g. C) into a low level language (e.g. assembly). In most cases, the output of the compiler (a.k.a. object code) is translated further by a program called a linker into an executable format.

A debugger is a software program that can be used to test and debug applications. The features of a debugger typically include the ability to control the application by single-stepping, stopping/breaking, viewing and altering memory and registers, etc. A debugger can be used to control real harware (through a hardware interface such as BDM, JTAG, etc.) or an instruction set simulator.

IDE stands for Integrated Development Environment. An IDE typically includes all the tools required to create, execute, and debug an application. For embedded systems this typically includes a text editor, project management system (e.g. Make), compiler, linker, and debugger. An IDE may also include hardware debugging tools, flash programmers, and more.