What is the N in statistics?

Hint: Generally, in statistics, the population refers to a set of similar items or events from where we conclude. The word sample refers to a set of objects which are collected from the population and a sample should be randomly selected and representative of the population. . Also, the size of the sample is always less than the size of the population.

Complete step by step answer:
 In statistics, the capital letter “N” is used to represent the total number of observations or the size of the population (i.e.) N is the total number of cases in all groups whereas the small letter “n” represents the sample size. That is, we can explain N simply as it is the number of elements in a population.
 Also, in the frequency distribution, the capital letter “N” is used to denote the sum of frequencies.
That is, in the formula $N = \sum {{f_i}} $ , N denotes the sum of frequencies and f is the frequency.
Mostly, the letter N is used to represent the population size.

Note: Generally, we use capital letters to refer to population attributes (i.e. parameters) and small letters to refer to sample attributes (i.e. statistics). For example
We often use the letter P to refer to a population proportion whereas the letter p denotes a sample proportion.
We use the capital letter X to denote a set of population elements and x to refer to a set of sample elements.
Similarly, we use the capital letter N to denote the population size; and n to sample size.