Even though the applications of quantum mechanics are somewhat understood , its foundations remain mysterious and are not properly understood. This is because quantum mechanics is a probabilistic theory. Probabilities had been used in understanding nature before quantum mechanics, but as an approximation. However, in quantum mechanics nature is fundamentally probabilistic, and the determinism we observe is only an approximation which holds at large scales. It is important to understand such a probabilistic theory, for both technological developments and a better understanding of nature.