What is a binomial distribution?
See the full explanation presented.
When we have 100 coins and we give those coins to a set of people in any manner, it is said that we are distributing coins.
In a similar way, when the total probability (which is 1) is distributed among the different values associated with the random variable, we are distributing probability. Hence, it is called a probability distribution. If there is a rule that determines what probability should be assigned to which value, then such a rule is called the probability distribution function.
The binomial distribution gets its name because the rule that determines the different probabilities are the terms of the binomial expansion.