Reset iOS vs Restoring from iTunes?

[iphonefreak450]

What is the difference between resetting an iOS device and Restore Stock iOS from iTunes?
What do they mean by restoring the stock iOS from iTunes as opposed to just resetting iOS to factory defaults?

Suppose your iPhone has been jail broken and you get bit by a malware, I read some articles that this needs to be cleaned by Restoring the iOS to stock using iTunes.

I am guessing that by just resetting the iOS to default factory setting only just resets or erases the settings to normal defaults as opposed to reinstalling iOS firmware.

Am I correct?

Thanks

 

[KALLT]

On iOS, a reset means that all user data is deleted. Restoring the device via iTunes will always download and restore the most-recent version, optionally a specific version as long as it is signed by Apple. There is no such thing as a factory reset here.

 

[C DM]

On iOS, a reset means that all user data is deleted. Restoring the device via iTunes will always download and restore the most-recent version, optionally a specific version as long as it is signed by Apple. There is no such thing as a factory reset here.

There is also resetting all settings, while keeping the data intact.