C++ void

hello. I am learning C++ by reading books, primarily C++ Primer Plus 5th edition, and watching tutorials on YouTube.
recently i started to learn about the void function and i ran into a brick wall. for some reason i simply just don't understand what it is or how and when to use it. for example in the book it says:

"Other functions take no arguments. For example, one of the C libraries (the one associated with the stdlib.h header file) has a rand() function that has no arguments and that returns a random integer. Its prototype looks like this:

int rand(void); // prototype of a function that takes no arguments

The keyword void explicitly indicates that the function takes no arguments. If you omit void and leave the parentheses empty, C++ interprets this as an implicit declaration that there are no arguments. You could use the function this way:

myGuess = rand(); // function call with no arguments"

So what I'm looking for is a simple explanation of void, a different way of explaining it, and some example code with comments to explain.
If you need more information on what i don't understand just leave a comment and ill reply.
Sorry if this seems like a dumb request but for some reason void just goes right past me.