III. The binary system and the computer
2. Binary number system
The binary system and the computer
You have now gained some initial experience with the binary system. The following video briefly summarizes the binary system once again, clarifies similarities with the decimal system we use and shows how this number system can be used to store all types of information.
A group of 8 bits is referred to as a byte. 1000 bytes then form a kilobyte, 1000 kilobytes a megabyte, 1000 megabytes a gigabyte, etc.
Even if we usually represent the values with 0 and 1, they can be represented within digital devices with anything that can be in two states: In RAM by power on / power off, on the hard drive by magnetized / non-magnetized or on the DVD by elevation / deepening.
From digi4all's point of view, the binary system is particularly exciting for one reason: at the lowest level, all data in digital devices, whether videos, text or numbers, is encoded using two states. And yes, programs are also encoded using only two states.
A bit sequence can have different meanings:
The bit sequence 1001000 (or: current on off off off on off off off off) can, depending on the interpretation, mean, among other things
- the Letter H or
- the number 72
Longer bit sequences can be used to describe texts, location data, pieces of music or even colors, for example. The color of a pixel in an image is determined by the three color components red, green and blue. Each of these colors is stored with 8 bits. This means that there are 28=256 possibilities per color (i.e. numbers between 0 and 11111111 in the binary system or 0 and 255 in the decimal system are possible).
Files
It is not just a number or a letter that is made up of zeros and ones, but every file on our computer. The decisive factor is the interpretation and therefore also the sequence of the zeros and ones. The sequence depends on the software that created the file. Many document types such as PNG, MP3 or ODF can be opened with different programs as they have been saved in a cross-software format. Others, such as PSD image files (Photoshop file) or iMovie project files, can only be opened with a specific application.