Assembly language is the most fundamental programming language around, as it’s a low-level language. This basically means that this language has little to no abstraction from the computer’s own architecture (meaning that the language’s functions are as close to the processor instructions as you can possibly get). That’s why it’s also known as the symbolic machine code.
In computer programming, assembly language (or assembler language), sometimes abbreviated asm, is any low-level programming language in which there is a very strong correspondence between the instructions in the language and the architecture's machine code instructions. Because assembly depends on the machine code instructions, every assembly language is designed for exactly one specific computer architecture.