What is the difference between a non-secure random number generator and a secure random number generator?

Question

As the title says: What is the difference between a non-secure random number generator and a secure random number generator?

Answer 1

With just a "random number" one usually means a pseudo random number. Because it's a pseudo random number it can be (easily) predicted by an attacker.

A secure random number is a random number from a truly random data source, ie. involving an entropy pool of some sorts.