Well I have been learning a lot about internal hard drvies lately and so far I can tell you that they are much better than external ones. Well first they get their power source and feed straight from the computer’s power source unit and the motherboard and they are always connected. Usually with external hard drives you will have to disconnect after a while or they get very hot. Internal hard drives is also good because it goes into your computer case and it becomes just one object so when you want to move it, you don’t have to move the case first and then the hard drive, just move the central unit.
Internal Hard Drives also have a Faster RPM or rotations per minute so they can record and move more files much faster. Of course external ones can catch up to that but they are much more expensive because of their high speed. External hard drives also use a USB cord to transfer files. This is true most of the time. And internal hard drives use a thick wire within the computer itself. If you look at it, you can assume that more files can be copied and transferred from and to the internal hard drive much faster than the external one even if the external hard drive has a faster RPM. So if you have some space left in your computer case, you are better off getting an internal hard drive rather than an external one.