Data is the driving force of any system that uses computers. Data availability is the reason the Internet became popular, and the ability to modify, store, process, and retrieve data is a major reason why computers are used in homes and businesses around the world. The term storage media usually refers to a means of storing data permanently, and numerous methods can be used to store data more or less permanently on several different media types. These methods include storing data magnetically on a disk or using optical disks.

We’ll look at various types of fixed and removable media, and learn how they store (and sometimes lose) data.We’ll also look at one of the most common data types that is saved to media and analyzed in computer forensic examinations: images. Image files com- prise digital photos, line art, and other graphical representations of people, places, and objects that can be saved to a storage device or other medium. As we’ll see, these files can be created in a variety of different formats, and numerous techniques and tools can be used to view and recover damaged files.

Overview of a Hard Disk

Although removable hard disks exist, most HDDs are designed for installation inside a computer, and for that reason they were referred to as fixed disks.To avoid having to purchase custom or proprietary hard disks to fit inside different brands of computer, standards were developed early in the PC’s history.These standards dictate the size and shape of the hard disk, as well as the interfaces used to attach it to the computer.These standards are called form factors, and they refer to the physical external dimensions of the disk drive.The most common form factors that have been used over the past few decades are:


5.25-inch These were the first hard drives that were used on PCs, and they were commonly installed in machines during the 1980s.
3.5-inch This is the common size of form factor used in modern PCs.
2.5-inch This is the common size of form factor used in laptop/notebook computers.

[img]hard-disk.png[/img]

http://www.futuristicsec.com/blog/2016/hard-disk/