As mentioned earlier, R Markdown extends Markdown. It offers many features to enhance it. There are various examples in R Markdown's documentation (http://rmarkdown.rstudio.com/gallery.html) where you may get a sense of what's possible. In this section, we will focus on code chunks, tables, graphs, local and global chunk options, and caching.
Extending Markdown with R Markdown
Code chunks
Code chunks are simply standard Markdown code blocks, which have a special syntax that uses curly braces ({}) along the top line of the block to send metadata to knitr, about how the block should be treated. The metadata sent is in the form of parameters with the key = value format. We'll cover more on this in the Chunk options...