Someday I hope to write a longer post on this, but today I need to type in this passage from Francine Prose's excellent Reading Like a Writer, which I recommend you get immediately if you're serious about writing, with the caveat that this is very advanced and dismayingly difficult stuff to emulate and will likely give you nightmares about your inadequacy as a writer.

The opening of "Dulse" by Alice Munro:

At the end of the summer Lydia took a boat to an island off the southern coast of New Brunswick, where she was going to stay overnight. She had just a few days left until she had to be back in Ontario. She worked as an editor, for a publisher in Toronto. She was also a poet, but she did not refer to that unless it was something people knew already. For the past eighteen months she had been living with a man in Kingston. As far as she could see, that was over.

        She had noticed something about herself on this trip to the Maritimes. It was that people were no longer so interested in getting to know her. It wasn't that she had created such a stir before, but something had been there that she could rely on. She was forty-five, and had been divorced for nine years. Her two children had started on their own lives, though there were still retreats and confusion. She hadn't gotten fatter or thinner, her looks had not deteriorated in any alarming way, but nevertheless she had stopped being one sort of woman and had become another, and she had noticed it on this trip.

Prose writes:

        ... Finally, the passage contradicts a form of bad advice often given young writers--namely, that the job of the author is to show, not tell. Needless to say, many great novelists combine "dramatic" showing with long sections of the flat-out authorial narration that is, I guess, what is meant by telling. And the warning against telling leads to a confusion that causes novice writers to think that everything should be acted out--don't tell us a character is happy, show us how she screams "yay" and jumps up and down for joy--when in fact the responsibility of showing should be assumed by the energetic and specific use of language. There are many occasions in literature in whcih telling is far more effective than showing. A lot of time would have been wasted had Alice Munro believed that she could not begin her story until she had shown us Lydia working as an editor, writing poetry, breaking up with her lover, dealing with her children, getting divorced, growing older, and taking all the steps that led up to the moment at which the story rightly begins.

        Richard Yates ... Here, in the opening paragraph of Revolutionary Road, he warns us that the amateur theatrical performance in the novel's first chapter may not be quite the triumph for which the Laurel Players are hoping:

        The final dying sounds of their dress rehearsal left the Laurel Players with nothing to do but stand there, silent and helpless, blinking out over the footlights of an empty auditorium. They hardly dared to breathe as the short, solemn figure of their director emerged from the naked seats to join them on stage, as he pulled a stepladder raspingly from the wings and climbed up halfway its rungs to turn and tell them, with several clearings of his throat, that they were a damned talented group of people and a wonderful group of people to work with.

        When we ask ourselves how we know as much as we know--that is, that the performance is likely to be something of an embarrassment--we notice that individual words have given us all the information we need. The final dying sounds ... silent and helpless ... blinking ... hardly dared to breathe ... naked seats ... raspingly.

This second passage is a mix of showing and telling, or telling disguised like showing. "Silent and helpless" is not really showing--how does an actor look helpless?  How does one see that they "hardly dared breathe"? A truly talented group would be described as "talented", not "damned talented"--is that little bit of information showing or telling?  This passage illustrates that the important question isn't whether you're "showing" or "telling", but whether you're using the right evocative words, in your narration and your dialogue.