Combining Data Frames with Differing Columns in R

Steven Sanderson does a bit of merging:

Combining data frames is a fundamental task in data analysis, especially when dealing with datasets that have different structures. In R, there are several ways to achieve this, using base R functions, the dplyr package, and the data.table package. This guide will walk you through each method, providing examples and explanations suitable for beginner R programmers. This article will explore three primary methods in R: base R functions, dplyr, and data.table. Each method has its advantages, and understanding them will enhance your data manipulation skills.

There are quite a few examples here, depending on whether you intend to join the datasets or perform a set operation such as union or intersect.