Issue: "I hear a lot about 'showing vs telling.' What does that mean?
Solution: Basically, telling is simply stating facts or basic impressions. Showing is describing the scene or action in some way that lets the reader really see it in their mind. Some examples should help.
Telling: “John came into the room all freaked out.”
Showing: “John ran into the room, nearly knocking Mary down. His eyes darted madly about, he was shaking horribly, and all he could say was, ‘The the the the...’ until he screamed and fell to the floor in a blubbering heap.”
Telling: "Gerald threw the dead man off, and then saw the man he'd disarmed coming."
Showing: "Gerald managed to throw the man off and leaped to his feet, dirk in hand. His attacker was already dead, Gerald’s axe buried in his chest. Gerald reached out, stopped, gritted his teeth, grabbed the axe, and jerked it from the man, splattering blood on his leggings and boots. He heard footsteps, whirled, and saw a man staggering toward him dragging a sword. Suddenly weary and ill, Gerald didn’t want to have to kill this man, but he had his orders. And he could see the hatred in the man’s eyes."
Second example from Year of the Dragon Lord, Book I of The Dragon Lord Chronicles, copyright 2015 Miles O'Neal, Round Rock TX.