Slice of life
A few months ago I sent you a story. While you offered some very encouraging comments, which I certainly appreciated, you nevertheless rejected the story because "it appears to be more in the 'slice of life' non-fiction genre than a short story." Frankly, I was puzzled by this. I hope you'll take a moment to explain to me why a non-fiction slice of life, with a beginning and end, cannot also be a short story.
Generally when I call something a "slice of life" I mean that it does not have a narrative arc, with inciting incident, complications, rising action, climax, and denouement. It often does not develop character, setting, or themes fully, but instead recounts an interesting anecdote in the life of the writer.
These "slices of life" can be well written and interesting, and often are. Many famous writers have also made good use of this form. I sometimes use it myself. And the successful Cup of Comfort" and Chicken Soup for the Soul pieces are often known as slice of life stories.
An ANECDOTE is a short non-fiction account of an interesting or humourous, and often biographical incident.
A SHORT STORY is a fictional piece that generally makes use of the narrative arc mentioned above.
There is no single, satisfactory definition of a short story. Most important, when sending out writing for publication, is to research the publications that focus on the sort of writing you like to do, and consistently send to them, as they are the ones with which you are most likely to have success.