Assembly language is a low-level programming language that serves as a bridge between human-readable code and machine code. Instead of writing in binary numbers that computers understand directly, assembly uses symbolic representations called mnemonics like MOV, ADD, and JMP to represent machine instructions. This makes it much easier for programmers to read and write compared to raw binary machine code.
The assembly process involves translating assembly language into machine code using a program called an assembler. The assembler reads the source code written in assembly language and converts each mnemonic instruction into its corresponding binary machine code. This creates an executable file that the processor can run directly. The assembler also handles tasks like resolving memory addresses and managing symbol tables.
Assembly language is platform specific, meaning it is tightly coupled to a particular processor architecture. Code written for x86 processors uses different instructions and register names compared to ARM or MIPS processors. For example, x86 uses registers like EAX and EBX, while ARM uses R0 and R1, and MIPS uses dollar-sign notation like t0 and t1. This means assembly code written for one architecture cannot run on another without significant rewriting.
Assembly language provides low-level control over computer hardware, giving programmers direct access to CPU registers, memory addresses, and hardware ports. This makes it essential for system-level programming such as operating system kernels, device drivers, and embedded systems. Assembly is also used in performance-critical applications where every CPU cycle matters, and in real-time systems that require precise timing control. The ability to directly manipulate hardware makes assembly indispensable for system programming.