Imagine you have a toy car and you can steer it in different directions. Now, let's say you want to see all the possible places your car could be on a map while you steer it. This is what we call a "locus".
In math, a locus is basically a set of points that follow specific rules or conditions. For example, if we think of a circle, the locus would be all the points that are the same distance away from the center.
Think about it this way: if you draw a line in the middle of a piece of paper and say "all the points on this side of the line are in the club and all the points on the other side are not in the club", you have made a locus.
Sometimes, loci can be very complicated and have many different conditions to be met. But the idea is always the same: we are describing a set of points based on some specific rules.