A strange notation

Question

In one of my papers I found a notation where 2 letters one under other are placed in brackets without any additional operation symbol - attached image (N m). What does this mean, is this a shortcut of summation?

Answer 1

$$\binom{N}{m}=\frac{N!}{(N-m)!m!} \text{ for } \ 0≤m≤N$$

Where the symbol "!" denotes the factorial