Monte Carlo: what is a seed? I have reached a chapter in the notes I am following where a program written in C++ is using a Monte Carlo method to estimate $\pi$. It mentions a 'seed', but does not say what this is. I have tried finding out what a seed is online, but I only seem to get results about 'why you should/shouldn't use a fixed seed', and unfortunately they have left me none the wiser as to what a seed actually is.

What is seed in this context?
The seed is an initial number of the pseudorandom number generator(PRNG) which is in fact fully deterministic. It returns a sequence of numbers that looks random enough for many purposes, but always generates the same sequence for given value.

In order to make simulation non-repeatable (returning always the same value) they advice different initial value for every simulation (this is what non-fixed seed means).


Image taken from here