I always see "fine-grained" in technology articles. What does it mean?
When used in the context of "fine-grained control", for example, it carries the connotation of "very precise": a volume knob that gives you fine-grained control means that you can set your volume to the exact level that you desire, you don't have to choose only between "too quiet" and "too loud".
I can't find a reference on this, but I think the etymology comes from sandpaper. Sandpaper is made with grains (originally sand) and if you make coarse-grain sandpaper you can quickly remove lots of unwanted wood, but the result is rough. If you make fine-grain sandpaper you can smooth or polish the wood to a high degree, with great control, but the work is slower because the smaller grains don't remove as much wood.
This metaphor extends into other tools where the tools offer control of minute details in order to achieve specific results.
The sandpaper analogy reads very well.
In pre-digital photography, "grains" of light-sensitive silver nitrate were used to capture images. It gets very technical, very fast, but I think it's safe to say "the smaller (finer) the grain, the higher the possible image resolution:
In Computer Science (as you're looking for),
- coarse-grained means 'monolithic'
- fine-grained means 'modulized' or 'devided into smaller pieces'
For examples, there are many kinds of architecture for web services:
- monolithic architecture is coarse-grained architecture.
- microservice architecture is fined-grained architecture.
These meanings are illustrated in this article.
I believe the original meaning came from gunpowder. Fine-grained powder (composed of small grains) burns faster and more reliably, but is harder to make and requires better materials. Thus it was used in primers but not in blasting charges, and was an obvious simile for control systems.
(NB this is entirely compatible with the sandpaper theory, and not unlike the wood theory).