The #inner_join function and its derivates are an essential tool to join/merge two data sets. Variations of the join functions are discussed and demonstrated in the video.
A series of short videos to introduce the most useful #R #rstats commands. In my scripts I use these with high frequency, so knowing them likely helps... Focus on #dplyr and #tidyverse in #RStudio.
See the playlist "R for beginners" for the full list.