1TB (Terra Byte) hard drive will fit many computing needs, whether you are a student, business person, marketing and many profession/business.
However, when using to record CCTV video you may need a bigger capacity of a hard drive. Besides capacity, the hard drive for CCTV needs to spin not too fast as it needs to works in a longer time. The performance nota priority but the endurance is.
How big is 1TB hard drive capacity?
External hard drive
Big capacity hard drives usually to store big files like movies and songs. Because the hard drive accessed relatively seldom, then people store it on an external system.
An external hard drive only attached to the computer when needed, not all the time need access to an external drive.
Internal Hard drive
An internal hard drive is physically not visible, its located inside the computer main unit or sometimes people call it CPU. Thi shard drive is the busiest hard drive compared to external one.