Dead code elimination is a process used in programming to remove code that does not affect the program's output. This includes functions, variables, or statements that are never executed or referenced. By eliminating this unnecessary code, developers can improve the efficiency and readability of their programs. This technique is often part of the optimization phase in compilers, which are tools that translate high-level programming languages into machine code. By streamlining the code, dead code elimination helps reduce the size of the final executable and can lead to faster execution times, ultimately enhancing overall performance.