ELI5: Explain Like I'm 5

Finite difference methods

Finite difference methods are like playing connect-the-dots, but instead of dots we use points on a graph, and instead of a pencil we use math equations.

Imagine you have a picture with a bunch of dots on it. If you connect the dots with lines, you can see the picture more clearly.

Now imagine that the dots on the picture represent different points on a line or a curved surface, and we want to know what the value is at each of those points. The value might be something like temperature, pressure, or fluid velocity.

With finite difference methods, we use math equations to estimate what the value is at each of those points based on the values of nearby points. We do this by dividing the space between the dots into small pieces and then using simple equations to estimate what the value is at each point based on the known values of points we've already figured out.

It's like guessing what the next dot in a connect-the-dots puzzle will be based on where the other dots are.

By using these methods, we can better understand the behavior of complex systems like weather patterns or fluid flow, even when we don't have all the data we need.