Types of storage media

Types of storage media

These days there are a range of storage media to choose from including CDs, DVDs, USB flash drives, memory cards, internal hard disks, external hard disks, network drives and on‐line file storage. Some are more suitable than others for a particular job, for instance a flash drive is great for quickly transferring relative small amounts of data from one computer to another.

Internal hard disks

All PCs are supplied with an internal hard disk. This is where the operating system (such as Windows) is stored. It is also were you store your data. When you install new applications, they are copied from CD or DVD to your internal hard disk.

External hard disks

As the name suggests these are secondary hard disks that you can plug into your computer. They are normally connected via a USB cable. They are available in a range of speeds and storage capacities and are an ideal way to backup your data, such as photos or movies.

CDs

Most computers are now supplied with a CD‐ROM (Compact Disc ‐ Read Only Memory) drive. CD‐ROM discs look exactly like music CDs but contain computer data instead of music. The advantage of a CD‐ROM is that it can hold a vast amount of data (equivalent to the storage capacity of over 450 floppy disks). The other big advantage of CD‐ROMs is that they are interchangeable. This means that you can own a range of different CD‐ROMs and choose which one to insert into your CD‐ROM drive.

DVDs

Short for "Digital Versatile Disk”. Similar to CD‐ROM drives but allows you to use DVD disks, which contain vastly more information than a traditional CD‐ROM disk. These also transfer the data from the disk to the computer far faster, allowing you to watch movies on your computer screen. A CD‐ROM can store 650 MB of data, while a single‐layer, single‐sided DVD can store over 4 GB of data.

Recordable CD & DVD drives

CD‐ROMs are read‐only devices, but increasingly people are purchasing a special type of CD drive unit which allows you to record data, music or video to your own CDs. These devices require the purchase of special CDs to which you can write, called CD‐R (Compact Disc – Recordable).