The emergence of a computer and, accordingly, virtual information stored on various electronic media, has led to the fact that we need more and more information storages. That is why for storage and exchange of information external media were invented, with the help of which data can be transferred to a personal computer.
Thus, the entire computer memory can be divided into two parts:
- own electronic (internal) memory;
- external PC memory located on third-party media.
Internal drives are called hard or fixed, they are built into the system unit of a computer and are usually called hard drives.
As a rule, the amount of data on third-party media is many times greater than the amount that is stored directly on the computer. Usually all programs and files are copied there, access to which is not required constantly, while the hard drive is intended for permanent storage of necessary information: operating system programs, documents, application programs, and so on.
At the moment, the external memory of the computer is represented by a huge number of various gadgets, but its first representative was a floppy disk, or, more simply, a regular diskette, that had already passed away. Such floppy disks are inserted into the opening of the computer’s drive, and their memory is 1.44 megabytes.
The development of multimedia has led to the emergence and development of other external media with which data (usually music, movies, games) get into a personal computer. This external computer memory is called laser compact discs (Compact Disks). Data is written to them in digital form. And if they are designed to write data at a time, they are called CD-ROMs, while discs designed to record and rewrite data multiple times are called CD-RWs. The capacity of a standard laser compact disc varies from 690 to two thousand megabytes.
External computer memory is read from laser discs using CD-ROM drives, which are internal and external.
DVDs have a larger volume, designed primarily for recording and transferring films. Separation on ROM and RW, as well as reading data from them, occurs on the principle of CD-ROMs.
There is another, the most popular type of data transfer at the moment - this is the external memory of the computer, which is called flash-memory. In this case, data is recorded on microcircuits, which ensures the highest data safety, as well as high speed of reading and writing information. Flash drives today have gained immense popularity not only as a computer gadget, but also as a data storage on mobile phones, cameras and other equipment where a device is required to record the received data. They come in various kinds of sizes, and can also have different sizes, up to several tens of gigabytes.
The external memory of the computer, which currently allows you to store the largest volumes, is called external hard drives. Their volume can be calculated in a few terabytes, and the reliability of data storage is appropriate. Such hard drives are connected to the computer using USB ports. In addition, their device allows not only to act as a storage of additional data, but also to act (with a constant connection to a computer) as an extension of the computer’s memory itself. Thus, there you can store the files necessary for the entire system. Such, for example, is external RAM.
Progress does not stand still, and external media is constantly improving. Data volumes are increasing, their convenience and reliability are increasing. However, it is always worth remembering that any technique can break at any time. That is why all the important information stored on the computer should be duplicated.