Quasiprobability is a big word that describes how people who are studying very small things, like particles, try to predict what might happen when they interact with each other.
Imagine you have a group of marbles and you want to figure out which ones will collide with each other if you shake them up in a jar. To do this, you would try to map out all the different ways the marbles could move around and bump into each other. But this can get really complicated and hard to keep track of!
Scientists use quasiprobability to help make predictions based on what they know about the marbles. Quasiprobability is like a special imaginary map that scientists use to predict what might happen when particles (like marbles) interact with each other.
The quasiprobability map lets them predict how particles will behave in different situations, even when it's really hard to keep track of everything. So even though you might never see quasiprobability in your everyday life, it's an important tool that scientists use to understand the tiny world around us.