Knowing about samsung galaxy 3 factory reset is not that important for users to know, as you hardly might require using it.
You should know that samsung galaxy 3 factory reset will put your phone back to the deault setting and configuration, which means that all of the installed applications which you downloaded will be wiped out.
There is a common way of doing this, for almost all of the galaxy models which will let your phone go into the factory default settings. The other way of using key combinations is also possible but is rarely used.
This can be done by keeping pressed the call button, end-call button and the volume rocker down key, all together while restarting the phone. This needs to be done in the switch off mode.
This will make your phone brand new, with all of the settings reverted to the original settings.
In cases when you encounter frequent crashes, or high threats of virus attacks, or when you find the phone hanging very often, you would find samsung galaxy 3 factory reset helpful.