What makes a computer a computer? Does a computer have to have certain pieces to be considered a computer? Consider the computers of the 1980s: they all included a display screen, a keyboard, and a processing unit. Over time, the computers have evolved into devices that do not look like a “typical” computer. Consider the iPhone or Android tablet, where the method of input relies on touch, without the use of a separate keyboard. How about the calculator watch displayed below; is it a computer?
Regardless of the form factorof the machine, four basic functions — input, output, storage, and processing — make a computer. Below is a display of how those functions work together.
So, as we consider the history of computers and the future of computers, we must consider what is and what is not a computer. Obviously, our desktops and laptops are computers, since they perform the input, processing, output, and storage functions. But so also are our cellular phones and smartphones, since they perform all these functions. What about our televisions? Many of these are complex computers as well, since they take information from our input using the remote control, process the information, and return an output, such as an on-demand movie. Many of these televisions also store the information, such as your favorite channels or even the video content itself for later playback. Even some thermostats are computers, since they also perform these functions, such as the “smart thermostats,” like the NEST and other popular brands. Remember, the main determination of whether something is a computer or not relies on the functions it performs: does it perform input, processing, output, and storage? If so, then it is a computer.