The top four brands of 1TB Hard Drives are amongst others Western Digital hard drives, Seagate hard drives, Toshiba hard drives, and Hitachi hard drives.
Hard disk drives
Mac laptops may likely have solid state drives (not hard drives). Those drives are 2.5" form factor and can be replaced by hard drives.
Hard drives last for many years
There are tons of kinds of drives. Floppy Disk Drives, CD-ROM drives, PATA Hard drives, zip drives, flash drives, DVD drives, SATA hard drives.... The list could go on and on and on...
Simpletech produce portable external hard drives. These range from small USB sticks, to larger external hard drives. Simpletech also produces mini versions of the portable hard drives
They store digital information in a relativly permenent form. Some hard drives called 'Hard Disc Drives' store data magnetically on a metal disc. Newer hard drives called 'Solid State Drives' store data electronically on flash memory.
Laptops use 2.5 inch hard drives, while desktops use 3.5 inch hard drives.
The first hard drives were only a couple of megabytes, while modern hard drives are 3TB and beyond. As technology progresses, hard drives will likely continue to increase in capacity. Therefore, not all hard drives are 2.5GB in size.
One can find cheap portable hard drives on online shops like Amazon or eBay. Just look for regular hard drives instead of flash drives, as these are more recent and cost much more then classic hard drives.
Keep the cats out of your hard drives. Just for fun, why not Google.
They all store information.