SharePoint ListItem Update vs SystemUpdate vs UpdateOverwriteVersion

Here is a simple table format to explain the differences among Update vs SystemUpdate vs UpdateOverwriteVersion vs SystemUpdate(true). 

This information is pretty much useful to look at the differences between the following SPListItem methods when working with event receivers or workflows.

	Update()	SystemUpdate()	SystemUpdate(true)	UpdateOverwriteVersion()
Updates the item in the database	ü	ü	ü	ü
Creates a new version	ü	û	ü	û
Updates the Modified and Modified By values	ü	û	û	ü