How to install a package in R
Packages is where the power of R lies. R has close to 10,000 packages available at CRAN. There is a package for just about anything in R. It is very easy to install packages in R.
Install a packages
Installing a package in R is simple. For example, the following statement installs the “plotly” package.
> install.packages("plotly")
Install multiple packages in one go
<strong>> install.packages( c("plotly","ggplot2") )</strong>
Install packages in R Studio
R studio makes life easy by providing a GUI for this.

you can specify multiple packages as well.

Where are these packages installed ?
These packages are installed in the library path which you can find out through
> .libPaths()
[1] "C:/Users/AjayTech/Documents/R/win-library/3.4"
[2] "C:/Program Files/R/R-3.4.3/library"
How can you load packages ?
Installing a library is one thing, but you have to load them to be usable by your programs. You load them as below.
# Note that there is no quotes this time.
> library(ggplot2)
How can you remove a package in R ?
It is as easy as installing a package
> remove.packages( c("ggplot2","plotly"))
Removing packages from 'C:/Users/AjayTech/Documents/R/win-library/3.4'
(as 'lib' is unspecified)
Or using the R Studio GUI.

How to get help on a particular R package
> help(package="caret")