Can a computer run without hardware?

Answer 1

Yes, It May Sound Little Awkward but it can run without hardware. A computer does not need to be electronic, nor even have a processor, nor RAM, nor even a hard disk. While popular usage of the word "computer" is synonymous with a personal electronic computer, the modern definition of a computer is literally "A device that computes, especially a programmable [usually] electronic machine that performs high speed mathematical or logical operations or that assembles, stores, correlates, or otherwise processes information". Any device which processes information qualifies as a computer, especially if the processing is purposeful. Historically, computers evolved from mechanical computers and eventually from vacuum tubes to transistors. However, conceptually computational systems as flexible as a personal computer can be built out of almost anything. For example, a computer can be made out of billiard balls (billiard ball computer); an oft-quoted example. More realistically, modern computers are made out of transistors made of photo lithographed semiconductors.

There is active research to make computers out of many promising new types of technology, such as optical computers, DNA computers, neural computers, and quantum computers. Most computers are universal, and are able to calculate any computable function, and are limited only by their memory capacity and operating speed. However different designs of computers can give very different performance for particular problems; for example quantum computers can potentially break some modern encryption algorithms (by quantum factoring) very quickly.

Answer 2

The computer is the hardware. Without the hardware there is no computer.