example #1 - wearing rubber soled boots, and walking on carpet. negative charges are created and when you reach for a doorknob those negative charges jump out, creating an electric shock or discharge.
example #2 - during a thunderstorm, water droplets, ice, and air move inside the storm cloud. this may cause negative charges to build up at the bottom of the cloud, and positive at the top. the negative charge at the bottom may induce a positive on the ground. this causes lightning, a form of electric discharge.