Possibly to take ext hdd and place it into computer?

Could you hypothetically remove the hard drive from a external harddrive and place it into a Desktop PC? What about a Pocket Drive and place it into a Laptop?
How do you know what size of the hard drive is and how it’ll fit into your computer?
Answer #1
You look at it man… Use your eyes!
BoomBoxCreations replied: Open up the case and have a look.
This man ^
Answer #2
Some, you can.
Others, you might not be able to.
for example, one of my WD external hard drives is a cavair blue or black or something, but didnt have any sata ports, the micro-usb port was built into the hard drive inside the case itself, another external hard drive (3.5″ internal), just had an adapter, it went straight into a SATA port no problems.
Also, some drives might need an adapter depending on what the drive is or what your PC can actually use.
Open up the case and have a look.
Concerning the sizes, if you have a big, bulky ext.hdd that requires an external power source, its most likely a 3.5″ drive (wont fit in most laptops)
Most of the smaller hard drives these days that dont need an external power supply would fit into a laptop (usually 2.5″) assuming they have a SATA connection or a connection that your laptop/desktop needs.