Does a CWM factory reset, wipe internal sdcard? Does a ClockWorkMod recovery backup, backup my media?

The story to this is that one day I booted up my phone (Samsung Galaxy S5) and all my system apps crashed right after I booted my phone, so for example a box would appear saying something like 'Unfortunately, Touchwiz has stopped'. The phone was already rooted, so I installed CWM for my phone and I backed up the phone to my external SD card. The whole reason why I backed up the phone is to tray and get my documents and photos back, but I don't know what exactly has been backed up, I know the system files has been backed up and the ROM. Has my media been backed up? I also need to factory reset my phone to use ODIN, but does a factory reset in CWM delete my internal sdcard? I researched this, and some people say yes and some say no.