A threshold is like the line on a swimming pool that shows when the water gets deep. Imagine playing in the shallow end where you can stand and play safely. The moment you cross the line, the water becomes deeper, and you might need to start swimming. That line is the threshold. It tells you when something changes from one thing to another.
Think about a doorstep. When you step over it, you go from inside your house to outside, or from outside to inside. The doorstep is the threshold. It marks the change between being in and out of your home.
Another way to think about a threshold is like a level in a video game. You play and play, and when you reach a certain level, things get more challenging. This level is like a threshold because it changes how the game feels.
A threshold can also be like the buzzer in a game show. When you answer a question correctly, the buzzer sounds, signaling you’ve crossed the threshold to get points. It marks the moment something important happens.