Assembly Language is a computer language that uses short words known as Mnemonics for writing programs.
Mnemonics is simply the name of a symbol and is used for REMEMBERING SOMETHING, for example, machine language instruction.
Assembly Language is used in applications such as C/C++ or written from scratch in a text file to address performance issues or direct hardware manipulation.
Assembly Languages have been famously used in Lotus 1 2 3 spreadsheet program applications and IBM PC DOS Operating Systems.
Four main types of Assembly Languages are:
1) Digital Signal Processor or DSP
2) Complex Instruction-Set Computer or CISC
3) Very Long Instruction Word or VLIW
4) Reduced Instruction-Set Computer – RISC
Gary gives a FANTASTIC explanation about Assembly Language: