I am about to download the cs50 2014 appliance but I've been wondering if I can download ISO file instead of OVA file as OVA is in bigger size, around 2 GB, and I can't download it with my internet connection speed. What I wanna know is if all the software pre-installed in both ISO and OVA are the same so I can do exactly the same as all the other guys using OVA file can do for all the problem sets of CS50. Thanks.
they are not the same.
the iso file allows you to either install in onto a machine or create a USB stick to boot from. There are some issues with doing this, one of them is that getting wireless working is very hard, unless you know Linux well. If you plan to use a wired connection it works rather well.
The OVA is a virtual machine, for which the appliance is optimized.