Show, Don't Tell

You have probably heard that phrase before, but what does it mean, how does one do it, and what does it add to your story? Today I am going to answer all three of those questions.
First: What does it mean to show and not tell?
It means to not use words that tell the reader what your characters are feeling, their personality, or the world they are living in. Don’t tell the reader that the little boy was happy, show them how he was happy. Make your readers think, "He is such a happy boy."
I really like this quote by C. S. Lewis: "Don't use adjectives which merely tell us how you want us to feel about the thing you are describing. I mean, instead of telling us a thing was 'terrible' describe it so that we will be terrified. Don't say it was 'delightful', make us say 'delightful' when we've read the description."
This ties into our second question: How does one show and not tell?
So now that we know what it means to show things to the reader, let's see what this looks like in action and how you can achieve this in your own writing.
Here are a few examples from my W.I.P., The King's Reign.
"After about an hour of sitting in each other’s company and sipping their tea, they heard a ruckus and small feet running in the castle. A door slammed behind them alerting them of the nosiest boy in the castle. Dominic."
This is showing that Dominic is a lively and energetic little boy.
Here is another example:
"'Peter,' Emily asked again in a soft voice, 'I heard you and Mother talking last night and I can't help wondering,' Peter handed her a sandwich, 'What is it?' he said, letting tomato juice drip down the corner of his mouth.  Emily crossed her arms and glared at him, 'You know it is not proper to talk with food in your mouth!'
"Sorry." He said wiping his mouth and smirking at his sister. 'What is it?' he said again."
See, this is showing you that the two characters are eating lunch, or at least Peter is. It is also showing you that Emily values manners, while her brother... not so much.
Here is yet another example:
"Cold, but refreshing wind blew through Peter’s hair as he nearly flew on the stout horse under him over the blinding white snow. He didn’t know where he was going but he didn’t care. All he knew was that he needed to get away from the Highlanders. They were gaining on him now, and he steered his horse to make a sharp right onto a path which lead into the woods just below those majestic mountains. He hoped to lead them off his trail. On and on he rode, bent forward and pushing his horse as fast as it would go. Peter knew that eventually the horse would eventually wear out and slow down but this didn’t happen for quite some time. "
What do you think Peter is feeling right now? The cold wind in his face. The pounding of his heart as he rode the horse at top speed. The relief of getting away from the Highlanders. You can probably get an image of what is going on and what he might be thinking.
So you see, to show your reader something can look different depending on the situation. You can describe a man in a way that puts the impression on the reader that he may not be a very good man, or you can drop little hints about your world that may be completely strange in the real world but an everyday occurence to the world that your characters live in.
Finally: What does showing add to your story?
In April, I was reading a really good book called Romanov by Nadine Brandis and she did such a good job of showing me what happened and how the characters felt that I felt like I was watching a movie. I mean seriously! It was that good!
Showing adds dimension to your story. Readers can relate better through it and are drawn in much more. It also adds quality to your book and makes it so much richer, as my friend said about a book she read, "like eating dark chocolate."
Now, I’m not an expert at this and I am still struggling to apply this to my own writing, but maybe we can work on this together and can give the world stories with descriptions so vivid that people will be longing for more.