What is the difference between re-sit and re-module?

A re-sit is a redo of the same assignment question and grades are capped at 50%. There is no need of attendance of class again. Do note that you should not have too much similarities of that from your first submitted work, or that will count as self-plagiarism. 

A re-module is a re-doing the entirety of the module from the start, which includes classes to attend. There is no grade cap on this.