Hard drive is a high-capacity, self-contained storage device containing a read-write mechanism plus one or more hard disks, inside a sealed unit.

The hard drive of a computer is a device that stores all the software installed on a computer, as well as all the data files created and used by this software. This includes any documents you have created and downloaded, such as photos and music. The hard drive is a form of permanent storage, rather than temporary memory such as random-access memory (RAM). This means that when you turn off the computer the files remain safely stored on the drive so you can use them again the next time you start your computer.

There are two general types of hard drives: hard disk drives (HDD), which use one or more rotating discs and rely on magnetic storage, and solid-state drives (SDD), which have no moving mechanical parts, but use flash memory like the kind found in USB flash drives. If you have a regular desktop computer, you most likely have a hard disk drive. Solid-state drives are more typical for high-end, expensive laptops.

Over the past five decades, hard drives have come a long way. Travel through time with us as we chronicle 50 milestones in hard-drive development–from product firsts to new technologies, and everything in between.

HDD         Before HDD

1956: IBM ships the first hard drive in the RAMAC 305 system. Invented by Reynold Johnson was introduced in 1956. The drive holds 5MB of data at $10,000 a megabyte. The system is as big as two refrigerators and uses 50 24-inch platters. It weighs over a ton. Amazingly, it was not rendered obsolete until 1962 and stayed on the market until 1969. The cost of storing data on this monster was $3,200 per month, which is over $160,000 in today’s dollars. Now, remember how you can get many times that storage space for free on Drop Box.

IBM ships the first hard drive in the RAMAC 305 system

1973: IBM announces the 3340, the first modern “Winchester” hard drive, which has a sealed assembly, lubricated spindles, and low-mass heads.

winchester

1979: IBM’s 3370 uses seven 14-inch platters to store 571MB, the first drive to use thin-film heads.

1979: IBM’s 62 PC, “Piccolo,” uses six 8-inch platters to store 64MB.

Picollo

1979: Seagate introduces the ST-506 drive and interface, which is then, used in all early microcomputer implementations.

1990: Western Digital introduces its first 3.5-inch Caviar IDE hard drive.

Caviar

1991: IBM introduces the 0663 Corsair, the first disk drive with thin film magnetoresistive (MR) heads. It has eight 3.5-inch platters and stores 1GB. (The MR head was first introduced on an IBM tape drive in 1984.)

2004: The first 0.85-inch hard drive, Toshiba’s MK2001MTN, debuts. It stores 2GB on a single platter.

Toshiba

2005: Toshiba introduces its MK4007 GAL, which stores 40GB on one 1.8-inch platter, fielding the first hard drive using perpendicular magnetic recording.

2006: Seagate completes the acquisition of Maxtor, further narrowing the field of hard drive manufacturers.

Maxtor

2006: Seagate’s Momentus 5400.3 notebook hard drive is the first 2.5-inch model to use perpendicular magnetic recording, which boosts its capacity up to 160GB.

2006: Seagate releases the Barracuda 7200.10, at 750GB the largest hard drive to date.

X SATA

2006: Western Digital launches its 10,000-rpm Raptor X SATA hard drive, boosting its capacity to 150GB and placing a flashy transparent window that allows specially designed computer cases to showcase its inner workings.

2006: Cornice and Seagate each announce a 1-inch hard drive that holds 12GB. The drives are slated to ship in the third quarter of 2006.

Today we have these latest best external hard drives such as:

Seagate Express

Seagate Expansion

This drive may look basic but the basic model boasts 2TB of storage for just under £60. You also get 3TB variants for £75 and 4TB for £100. It’s our pick of the bunch for sheer space and simplicity. We think it’s probably best suited for storing files you access rarely, such as archive photos. A new 2015 variant changes the rather staid design for a chequered one, but is slightly more expensive for the same capacities.

Samsung MM3

Samsung M3

With hard drives, it’s value that often wins the day and while Segate’s Expansion does it on sheer bang for your buck, Samsung’s M3 is the best value drive in the portable segment. It’s £46 for 1TB, and £65 for 2TB. A 500GB version is also available but we don’t recommend it, as it’s not much cheaper than the 1TB version. Like many portable drives, it’s USB powered. It also features some PC software that enables you to password protect your drive.

MM3

Toshiba Canvio Basics

One of the only drives where the 500GB is significantly cheaper than the 1TB, which means you can have fantastic portable storage for not much over £30. The 1TB is also slightly cheaper than the Samsung, but it still loses out the the Samsung in this list simply because, well, it’s also a bit ugly. And for a portable drive, you want something that you’re not afraid to get out of your bag.

The capacity of hard drives has grown exponentially over time. When hard drives became available for personal computers, they offered 5-megabyte capacity. During the mid-1990s the typical hard disk drive for a PC had a capacity of about 1 gigabyte.

As of December 2014, desktop hard disk drives typically had a capacity of 500 to 4000 gigabytes, while the largest-capacity drives were 8 terabytes

Source: PcWorld