Good! Now let's solve another problem: what if we want to count the number of each value in a vector?

You can easily solve this by using the `summary()` function with the factor variable as the parameter. This will return the number of occurrences of each possible value in the factor. For example,

# Factor variable
curr_f <- factor(c('USD', 'EUR', 'AUD', 'NOK', 
                  'CHF', 'EUR', 'AUD', 'EUR'))

# Show summary
summary(curr_f)

The output will be:
```
AUD CHF EUR NOK USD 
  2   1   3   1   1 
```
Note that the order of possible values is the same order that you set within the `factor()` function (if you don't set the order, then math laws or alphabet work)

In the first section, you will consider the very basics of R - outputting and performing basic operations. You will finish the section with the variables theory.

In the second section, you will learn the vector class in R, which represents single values too. You will consider the main data types for single values and how to work with multiple values of a kind at once.

Factors (or categorical variables) are widely used in real life. These are blood types, currencies, nationalities, brands, etc. Unlike numerical variables, factors are limited to a finite number of values.