To find out what packages are already installed use
To find out more about a particular package use library(help=FOO). So to find out more about the stats package use
To find out the details of a particular function in a package use help(FOO, package = PKG). So to find out about the lm function in the stats package use
The help window displays information about the function in the right pane, and lists all other available functions on the left.
If you need to find a package that provides a particular function use help.search(“keyword”).
So to look for packages that provide regression functions use
or packages that will fit linear models
In all cases a new window will open displaying a list of matches. Again the help(FOO, package = PKG) command will describe what the functions available in that package will do.
All R commands that can be typed in exactly as they shown are displayed in red.
The word FOO is often used within R (and in many other computing contexts) as a way to indicate that FOO should be replaced by a real instance of something. In this case a function name is needed. Technically, I believe FOO is used as a metasyntactic variable.