R Markdown is an R package you can use with RStudio to create dynamic documents, presentations, and reports from R. Documents created with R Markdown are fully reproducible. They can be automatically regenerated whenever underlying R code or data changes.
R Markdown is an increasingly popular way to present a code block as a self-contained R environment where variable values can be changed, the code rerun and the corresponding output seen. For example, teachers may send exercises in R Markdown documents for students to fill in and submit for review. Some people refer to this capability as “notebook” functionality although it currently lacks inline output for code chunks that would make it even better. We plan to update R Markdown with this capability soon.
To see how R Markdown could work for you as a notebook we suggest you watch the webinar here: http://www.rstudio.com/resources/webinars/archives/
If you prefer to work through a website at your own pace, you can visit: rmarkdown.rstudio.com.