For documents and a few thousand photos, a 128 GB drive like the Kioxia U202 is enough. To back up a whole computer or a video library, move to a 1 to 5 TB external drive, like the Seagate Expansion.
External hard drive or USB stick?
A stick slips into a pocket to carry files around. An external drive, like the WD My Passport 4 TB, holds far more data for less per GB and is mainly used for backups.
How do I back up properly?
Keep at least two copies of important files on two different devices, for example the computer and an external drive. Back up on a fixed schedule, weekly or monthly.
Is an external hard drive sensitive to knocks?
Yes, especially while it is spinning. Do not move it mid-copy, lay it flat and eject it before unplugging the cable.
Which storage to choose?
To carry files: USB flash drives, from 32 to 256 GB, like the 128 GB Kioxia TransMemory U202.
For a phone, camera or action cam: microSD and SD memory cards, like the 256 GB Samsung EVO Plus.
To back up a computer: external hard drives such as the Seagate Expansion from 1 to 5 TB or the Western Digital My Passport 4 TB.
To reuse an internal drive: a hard drive enclosure turns it into a USB external drive.