The pandas merge operation combines two or more DataFrame objects based on columns or indexes in a similar fashion as join operations performed on databases. The goal is to have a new dataset while the sources remain unchanged. The pandas merge function can be used for inner, outer, left, right, and cross joins, and it's often the most-used method or function for combining datasets in pandas. An alternative to merge in pandas is the concat() and join() methods, which are used for different purposes such as stacking DataFrames vertically or joining data tables along indexes. The choice of method depends on the specific need for combining datasets before making an analysis.