 At the most basic level, the myriad transistors in a computer are essentially tiny digital schemes, each with two types: the “on” and “off” settings of the transistor-capacitor switch. The settings are discrete and distinguishable, as are their compliance classes, of 1s and 0s. The ubiquity of binary code in computer processing is a consequence of the fact that a digital computer is essentially a vast collection of on-off switches. A particular sequence of 1s and 0s realized at a particular time in virtue of the requisite arrangement of transistors is a binary instance of a particular number, interchangeable with all other instances of the same number and with no instances of different numbers. The difference between instances of one number and instances of other numbers is strictly limited to the difference in the ordering of 1s and 0s. In other words, Goodman’s condition of finite differentiation is clearly met. In turn, the numbers can refer to other values, including the light-intensity values of an image. A computation simply involves the generation of output strings of binary digits from input strings in accordance with a general rule that depends on the properties of the strings (Piccinini 2008). The modern (digital) computer encodes both data and instructions of human readable code and assembly languages as sequences of binary digits, or bits, and allows for the internal storage of instructions. This makes the computer essentially programmable in the sense that it can be modified to compute new functions simply by being fed an appropriate arrangement of bits.