4. Has a rigid cell wall made of peptidoglycan (except for the mycoplasma). This cell wall is thick in Gram-positive bacteria and thin in Gram-negative bacteria. It is the thickness of the peptidoglycan that accounts for the ability/lack of ability to retain the crystal violet used in the Gram stain.
Computer hardware is the physical parts or components of a computer, such as the monitor, mouse, keyboard, computer data storage, hard disk drive (HDD), graphic cards, sound cards, memory, motherboard, and so on, all of which are physical objects that are tangible.
The central processing unit is the most important hardware component of a computer system. It is also known as the CPU, the central processor or instruction processor, and the main microprocessor in a microcomputer. computer is system of hardware devices organized according to the following system functions. 1  Input. 2  The input devices of a computer system include keyboards, touch screens, pens, electronic mice, optical scanners, and so on.