In slides, a command (we'll also call them code or a code chunk) will look like this
print("I'm code")
[1] "I'm code"
And then directly after it, will be the output of the code.
So print("I'm code")
is the code chunk and [1] "I'm code" is the output.
These slides were made in R using knitr
and R Markdown
which is covered in later modules, like reproducible research.