A random-access machine is like a big toy box that you can play with. Imagine you have lots of toys, and you keep them in a big box. But you want to play with a specific toy, and you don't want to dig through the whole box to find it. So, you ask your mom to make a toy box with compartments, so you can store each toy in its place.
A random-access machine is like having a toy box with lots of compartments. A computer works like a random-access machine, too. It can store lots of information like numbers, words, and pictures in compartments called "memory cells." Each memory cell has its own number, just like the compartments in a toy box.
When a computer needs to use a particular piece of information, it can go straight to that memory cell, just like you can go straight to the compartment to get your toy. To tell the computer which memory cell to use, we give it a number, which is called its address.
For example, if you want to add two numbers together, you can store them in two different memory cells-called A and B. Then, you can tell the computer to add them together by telling it to go to memory cell A, get the number there, go to memory cell B, get the number there, and then add them together. The result of the addition can be stored in another memory cell, called "C".
So, a random-access machine is like a toy box with compartments, but instead of toys, it stores information, and each piece of information has an address. Just like you can easily find your toy in the toy box, a computer can quickly retrieve information by going to the right address.