A one shot is simply a story that is no longer than a chapter. In other words, it is a short story. The phrase 'one shot' means that the story is a one-off, and that no more has been intended to be added to it after the first chapter has been posted.
One shots vary in length. Some can be very short, like 500-1000, whereas others can be very long, like 10,000-20,000 words. Sometimes, if the author receives very positive reviews about the one shot, they will continue the story and add another chapter, making it a two shot, or they may even turn it into a full story.
One shots in fan fiction vary in their content. They usually focus on a particular character's point of view, on a particular event or it could even be a short poem. Some one shots are created as part of a challenge set by other readers.
One shots vary in length. Some can be very short, like 500-1000, whereas others can be very long, like 10,000-20,000 words. Sometimes, if the author receives very positive reviews about the one shot, they will continue the story and add another chapter, making it a two shot, or they may even turn it into a full story.
One shots in fan fiction vary in their content. They usually focus on a particular character's point of view, on a particular event or it could even be a short poem. Some one shots are created as part of a challenge set by other readers.