difference between createPartition and createfold functions

Hello,

I'm trying to separate my dataset into 4 parts with the 4th one as the  
test dataset, and the other three to fit a model.

I've been searching for the difference between these 2 functions in  
Caret package, but the most I can get is this--

A series of test/training partitions are created using  
createDataPartition while createResample creates one or more bootstrap  
samples. createFolds splits the data into k groups.

I'm missing something here? What is the difference btw createPartition  
and createFold? I guess they wouldn't be equivalent.

Thank you.

Bonnie Yuan