It is useful to be able to move data from one location to another. For example between school and home.

To do this, you need to use 'Portable Data Storage'

These are some popular portable storage media:

• Floppy Disk
• CDROM
• Tape
• Zip Disks
• DVD Read-Write
• Removable Hard Disk
• USB Key memory sticks.

Each on has its advantages and disadvantages. For example a floppy disk is very easy to use but it can only hold a relatively small amount of data (1.44 Megabytes).

DVD-R on the other hand can store a huge amount of data (4,700 Megabytes single sided) but it is much more awkward to record the data. It is also a bit of overkill if you only have a small amount of data.

Removable Hard disks are a good option for storing your entire data set, but it is very expensive compared to the other options.

USB Key Memory is becoming very popular now and may eventually replace the floppy disk as the most convenient device. You just plug it into an USB port and it then appears as another drive on your computer. You simply drag and drop your files into it. Cheap ones can store about 32 Megabytes whilst the more expensive ones can store more than a Gigiabyte.

CD-ROM is a good compromise - it is relatively easy to write data onto and can store up to 680 Megabytes. The disks are quite cheap and any CDROM drive can read them.

Tape is not very popular because you have to read it from the beginning of the tape to get to your data. It is also slow compared to the other options. Tape is often used to archive backup data.

Zip disks can store up to 250 Megabytes but they are not so popular these days as the USB Memory stick is more convenient and CDROM can store more data.