In the times before RStudio, it was very hard to manage bigger projects with R in the R console, as you had to create all the folder structures on your own.
When you work with projects or open a project, RStudio will instantly take several actions. For example, it will start a new and clean R session, it will source the
.Rprofile file in the project's main directory, and it will set the current working directory to the project directory. So, you have a complete working environment individually for every project. RStudio will even adjust its own settings, such as active tabs, splitter positions, and so on, to where they were when the project was closed.
But just because you can create projects with RStudio easily, ...