1. (primarily used by C/Unix programmers, but spreading) It is received wisdom that in most programs, less than 10% of the code eats 90% of the execution time; if one were to graph instruction visits versus code addresses, one would typically see a few huge spikes amidst a lot of low-level noise. Such spikes are called "hot spots" and are good candidates for heavy optimisation or hand-hacking. The term is especially used of tight loops and recursions in the code's central algorithm, as opposed to (say) initial set-up costs or large but infrequent I/O operations. See tune, bum, hand-hacking. 2. The active location of a cursor on a bit-map display. "Put the mouse's hot spot on the "ON" widget and click the left button." 3. A screen region that is sensitive to mouse clicks, which trigger some action. Hypertext help screens are an example, in which a hot spot exists in the vicinity of any word for which additional material is available. 4. In a massively parallel computer with shared memory, the one location that all 10,000 processors are trying to read or write at once (perhaps because they are all doing a busy-wait on the same lock). 5. More generally, any place in a hardware design that turns into a performance bottleneck due to resource contention. [Jargon File] (1995-02-16)

also hotspot (hot spots)

In geology, hotspots (or hot spots) are volcanic locales thought to be fed by underlying mantle that is anomalously hot compared with the surrounding mantle. Examples include the Hawaii, Iceland, and Yellowstone hotspots.

A hot spot in computer science is most usually defined as a region of a computer program where a high proportion of executed instructions occur or where most time is spent during the program's execution (not necessarily the same thing since some instructions are faster than others).

Spots (also known as "spotting", "knifers", "knife hits", "knife tokes", "dots", "hot knives", "kitchen tracking" "blades", or "bladers") refers to a method of smoking cannabis."Handbook of Pharmacy Education", Harmen R.

<hardware> The connection and disconnection of peripherals or other components without interrupting system operation. This facility may have design implications for both hardware and software. [More detail?] (1997-03-15)

Hot swapping is the replacement or addition of components to a computer system without stopping, shutting down, or rebooting the system; hot plugging describes the addition of components only. Components which have such functionality are said to be hot-swappable or hot-pluggable; likewise, components which do not are cold-swappable or cold-pluggable.