Expander graph

Have you ever played with a toy balloon that when you squeezed, it would expand and get bigger? An expander graph is a bit like a balloon that expands when we stretch it out. But instead of being made of rubber, it is made of lots of little dots (we call them vertices) that are connected by lines (edges).

An expander graph is a special kind of graph where no matter how hard we try to stretch it out, it never loses its shape. This means that even if we remove some of the dots, the remaining ones will still be strongly connected!

Expander graphs are really important in computer science because they have a lot of useful properties. For example, they can be used to design computer networks that are really good at transmitting data quickly and reliably. They can also be used to encode messages so that they can be sent securely over the internet without anyone being able to read them.

All in all, an expander graph is a really cool toy that helps us build strong and efficient computer systems!