analog

Analog (also spelled analogue in British English) has two main flavors of meaning. In everyday and academic writing, it can mean “similar” or “parallel,” especially when you’re drawing comparisons. In technical contexts, it refers to systems that use continuous signals to represent information. Imagine drawing a line on a piece of paper—smooth and unbroken. That’s the feel of an analog signal: it can take on any value within a range.

Historically, analog relates to the idea of proportion and correspondence. You might say two situations are analogous if they share key similarities—like comparing the challenges of building a house to those of raising a family. As a noun, an analog can be a comparable counterpart: in biology, for instance, “analogs” can be features that do similar jobs in different species (and you may also see the spelling analogue used this way, especially in British English).

In modern usage, though, you’ll most often meet analog in the “not digital” sense. An analog audio recording uses grooves on a vinyl record where the depth and shape of the groove directly correspond to the sound wave. This is different from a digital recording, which converts the sound into numbers (bits) stored as discrete values. Similarly, older thermometers used mercury—the height of the mercury column was an analog representation of temperature.

Today, we often use analog in contrast to digital. While digital technology dominates many areas, analog signals remain important for things like radio transmission and many kinds of sensors. You might hear about analog synthesizers, which create sound using continuously varying electronic circuits, or discuss the warmth and character people associate with analog photography compared to digital images.

So whether you’re talking about a parallel idea (“That’s an analog of this situation”) or the way information is represented electronically, analog points to correspondence and continuous variation—a smooth flow rather than distinct steps.