Assembly language

Assembly language represents processor instructions with mnemonic operations and symbolic names for registers, constants, and memory addresses. Its instructions map closely to a particular processor’s machine code.

Assembler: A program that translates assembly-language source into machine code or relocatable object code. It converts mnemonics and symbolic addresses into encoded instructions and references.
CPU register: A small, fast storage location built into a processor and directly named by many instructions. Assembly instructions commonly name registers as operands and destinations.
Embedded system: A computer system built into a larger device to perform a dedicated set of functions. Firmware for constrained devices sometimes uses assembly for tight control of hardware and resources.
C (programming language): A general-purpose programming language that provides direct access to memory and compiles to machine code. C retains low-level control while expressing most operations more portably and compactly.
Instruction set architecture: The specification of a processor’s instructions, registers, data types, and programmer-visible behavior. An assembly language expresses the operations defined by a particular processor architecture.
Addressing mode: A rule specifying how an instruction identifies or computes the location of an operand. It determines how assembly operands designate registers, constants, or memory.
Bootloader: A program that initializes a computer enough to load or start an operating system or another program. Early startup code may run before ordinary compiled software is available.
Compiler: A program that translates source code from one programming language into another form, commonly machine code. Compilers can generate machine code from higher-level source instead of hand-written instructions.
Machine code: The binary encoding of instructions and data that a processor can execute directly. This is the encoded form an assembler produces from most assembly source.
Opcode: The part of a machine instruction that specifies the operation to perform. Each assembly mnemonic corresponds to an operation encoded by an opcode.

Linked from 12 pages