What are the differences between hardware and software?
Computer hardware is any physical device, something that you are able to touch and software is a collection of instructions and code installed into the computer and cannot be touched. For example, the computer monitor you are using to read this text on and the mouse you are using to navigate this web page is computer hardware. The Internet browser that allowed you to visit this page and the operating system that the browser is running on is software.
Can a computer run without software?
In most situations, yes, a computer can run without software being installed. However, if an operating system or interpreter is not found on the computer it would either generate an error or sit at a black screen. Installing additional programs onto the computer after the operating system has been installed will only give that computer additional abilities. For example, a word processor is not required, but will allow you to create documents and letters.
Can a computer run without hardware?
Depends on the hardware. Almost all computer setups will require at least a disk drive (e.g. hard drive), display, keyboard, memory, motherboard, processor, power supply, and video card in order to function properly. If any of these devices was missing or had problems, an error would be encountered, or the computer would not start. Adding other hardware such as a disc drive (e.g. CD-ROM or DVD), modem, mouse, network card, printer, sound card, speakers, etc. are not required, but will give the computer additional capabilities.