A programming language that is one step away from machine language. Each assembly language statement is translated into a machine instruction by the assembler. Programmers must be well versed in ...

Assembly, or asm, features "a very strong (generally one-to-one) correspondence between the language and the architecture's machine code instructions," according to Wikipedia.

Five hundred lines written by a seasoned programmer can perform the same processing as two thousand lines of code by another. See assembly language, machine language, microcode and compiler.

Whereas compilers and interpreters generate many machine code instructions for each high-level instruction, assemblers create one machine code instruction for each assembly instruction.