install.packages() and give it the name of the package you want to install. To install ggplot2, run:
At this point you may be prompted to select a download mirror. It’s usually best to use the first choice, https://cloud.r-project.org/, as it is a cloud-based mirror with endpoints all over the world.
If you want to install multiple packages at once, you can pass it a vector of package names. For example, this will install most of the packages used in this book:
install.packages(c("ggplot2", "gcookbook", "MASS", "dplyr"))
When you tell R to install a package, it will automatically install any other packages that the first package depends on.
CRAN (the Comprehensive R Archive Network) is a repository of packages for R, and it is mirrored on many servers around the world. It is the default repository system used by R. There are other package repositories; Bioconductor, for example, is a repository of packages related to analyzing genomic data.