what is srand?

Answer 1

seed-rand, you will use this to set the random seed in the program for example
srand(155);
std::cout<<(rand()%100+1);

the above will output 1-100 however since the seed is 155 every time it will output the same number, instead you can input time as the random seed using the ctime library.
srand(time(0));
the above seed will give a different possible output everytime.

Answer 2

yea relatively like that

Answer 3

a truly random function