KS3 ICT Practice Test: Data Storage — Flashcards

Data storage is important to computers in many ways. The earliest form of data storage was to use cards with holes punched in them. These could then be fed into a computer when they were needed and the data could be processed. Some of the early computers even required cards to contain the instructions that told them what to do with the data. As computers developed, magnetic tape, like that used for tape recorders, was used to store both data and programs. Accessing data like this was slow and the tape reels had to be moved backwards and forwards over a 'head'. The head read the magnetic tape and was fixed in place.

The next development for data storage was to replace the reels of tape with magnetic disks. These were smaller than the tape reels and the data could be accessed faster as they were read by moving both the disk and the head. Hard disk drives are based on this system and are found in almost all computers. These are being replaced by data storage devices like USB flash drives and solid state drives (SSDs). These are faster and more resistant to damage than hard disk drives.

Computer data storage provides one of the core functions of the modern computer, that of keeping valuable information safely and accurately. Each time data is transferred, it is possible that it may be changed slightly due to defects in the system. We say that data altered in this way has been corrupted. When saving any data, it is always good to have a separate back-up copy. This could be on an external hard drive, USB flash memory or something like a CD-ROM.

Data storage is normally organised into records and fields in a database, text files or images. The simplest database is known as a flat file. This is a file in which the data is stored in one single table. More complex databases contain data in different tables and are called relational databases. These are very useful where one item can have several different pieces of data stored about it e.g. the different books borrowed from a library by one person.