The save() function saves the serialized version of the objects supplied as arguments along with the object name. The subsequent load() function restores the saved objects, with the same object names that they were saved with, to the global environment by default. If there are existing objects with the same names in that environment, they will be replaced without any warnings.
The saveRDS() function saves only one object. It saves the serialized version of the object and not the object name. Hence, with the readRDS() function, the saved object can be restored into a variable with a different name from when it was saved.