Explain · Like I'm five version
Redstone in Minecraft in terms of household electrics
Redstone is basically a long trail of fairy lights that helps you turn things on and off in your game.
Think of Redstone dust like the wires hidden inside your walls at home. When you place a block of Redstone on the ground, it acts just like a copper cable. It carries a little bit of power from a battery, which is a Redstone torch, all the way to a lamp or a door. If the wire is broken or cut, the power stops, and your light will not shine. It is exactly like a plug that has fallen out of the socket behind the sofa.
To make things move, you use a switch like a lever or a button. Pushing the button sends a signal through the red dust to a sticky piston. This piston is like the motor that pulls your curtains shut in the evening. It pushes a heavy block out of the way so you can walk through a secret door. If you forget to connect the wires, your secret door will just stay shut and you will be stuck outside in the rain.
You can even make things go blinky or stay on for a while by using a repeater. This works like a little delay switch that holds the power for a second. It is just like the timer on the microwave that dings when your beans are hot. Once you learn how to lay the dust, you can build a whole house that turns itself on when you walk through the front door.
Where the analogy breaks downReal wires are insulated to prevent fires, whereas Redstone dust is just loose powder that sits openly on the floor.