Great word. Focus is important, or we'd never get anything done. I think people are pretty clear on the meaning…maybe not so much in the application.
You hear it a lot, especially from athletes. A single mindedness. The ability to be free from distraction, to attend to activities with a serial approach. With the implication being that there's a reward for such behavior: If you can concentrate on one thing, you will achieve desired outcomes, and quickly.
I can't recall ever discussing focus with artists, but you need only watch them at work to see that focus is a requirement for their productivity. If you're moved to create in the artistic world, focus will find you, you won't have to go looking for it. Doesn't matter what skill level or experience you have. I'm a total hack, but when I go into create art mode, I don't mess around. I'm working on one thing and one thing only because the inspiration flows from a singular source.
It seems to me that meaning is not an issue with understanding focus, rather it's the degrees of focus that people bring to bear that confuses. Whereby focus connotes a spectrum, if you will. Athletes have high focus, burger flippers not so much. One can be extremely focused or partially focused. The degree to which you can focus depends on whether or not you have programmed focus into your behavior, like athletes do. They practice being focused, just as they are practicing the specific skill(s) required.
Focus, like any other word, can be misused. When I was in treatment at Compass in Tucson, each person in the group was expected to announce their daily goal at the morning kick-off group. Seven out of ten people would say, "All I'm gonna do is stay focused." These were the most chronic abusers, real gutter types, people like me who were no help to themselves, and repeatedly found themselves in-patient despite their declarations to stay focused and sober. (I always had specific objectives for each day, which would articulate with my usual affinity for big words, thus earning a reputation as a alcoholic-savant.) The word focus was a shield, or a blind, to hide behind because we had no phucking idea what to do next to break the cycle and save our own asses from premature death.
Like I say, athletes build focus through regular practice. It's possible for people, even those stuck in the revolving door, to adjust their focus. To make it more effective at the same time you're making it more available. Defeating distraction takes some doing, though that is essential if you're going to be able to build and maintain focus. How does one go about eliminating distractions?
First, like everything else, you can overdo it. It's impossible, even inadvisable, to maintain focus non-stop. It's like boxing—you can't keep your guard up the whole match. That's why you move, to take a step out of reach and drop your guard. (Try holding your arms up for five minutes without a break, you'll get the picture.) It's important to be able to drop in and out of a focused state—there's some evidence that people have a requirement for a certain amount of boredom to spur creative and innovative ideas. Suggestions for 'span' of focus are all over the map. Experts write that human focus decays after twenty minutes of concentration. Other studies say it's longer, some much longer.
I say how long you use focus is variable and task/challenge specific. (I can focus on sex a lot longer than I can pulling weeds from the yard.) The point is: try not to get hung up on the process. Eliminating distractions is the over arching objective.
One excellent way to train/program focus is to practice meditation. Clearing the mind is the requirement, and the better you get at dispelling the incessant parade of thoughts in your head, the better command you'll have over focus.
Another incremental step would be to address focus through the lens of habit. People are finding great success with framing their behaviors in term of habit—and as a delightful coinkydink, there's a wave of habit-mongering going on to support your habit overhaul. Whether they're "Tiny Habits" or "Atomic Habits" there are lots of resources available, and I can vouch for the habit transformation from personal experience. (I prefer James Clear's techniques.)
I concede that factors may be present that inhibit the development of better focus. If you are in intense pain, say, a bad tooth or anal abscess, focus is difficult to achieve. With level seven and above pain, that is your focus. There can also be mental deficits (through damage or disability) that sub-optimize the capability to focus. And, for sure, the pandemic is going to make it hard to focus. Just keep in mind…
When you're up to your ass in alligators, it's hard to remember you came to clean up the swamp.