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.
Basic Elements of a Computer System. A computer system is an interconnected system of components that transmit electronic information between them to accomplish a task given to the computer. Computer systems require several critical components to function, all of equal importance. The hardware components of the computer are the parts you can see and touch.