Since you had learned how to add elements to a vector, wouldn't it be logical if you knew how to delete elements out of a vector? Everything went to this.

To remove an element out of a vector, place the `-` sign before the index of the unnecessary element. Note that this will not overwrite your vector, so the reassignment most likely comes in handy. Place a vector of indices right to the `-` sign to remove multiple elements. For example, we can remove the third element for the `grades` vector.

# Vector of grades and names
grades <- c(80, 75, 95, 100)
names(grades) <- c('Math', 'Physics', 'English', 'Literature')
# Remove the third element
grades[-3]

The result will be:
```
      Math    Physics Literature
      80         75        100
```
Also, we can delete the second and the fourth element of the initial `grades` vector.

# Vector of grades and names
grades <- c(80, 75, 95, 100)
names(grades) <- c('Math', 'Physics', 'English', 'Literature')
# Remove the third element
grades[-c(2,4)]

This time the result is:
```
   Math English
   80      95
```

> Remember, the actions represented in the examples will not rewrite the vectors. If you want to have changes saved, you need to reassign the result to the same vector (or a new one, if required).

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.