Nowadays, most operating systems rely on graphical interfaces and are designed to be user-friendly. Using just a few mouse clicks, the most important functions are easily accessible for users. Menu navigation tends to be intuitive. However, this was not always the case. Right at the start, when computers were used for scientific and military purposes, operating systems were not yet in use. All tasks were solved by the machine itself without a network layer. But with the launch of the first PCs that were not the size of a wardrobe, operating systems became part of the standard configuration.
The very first operating systems did not have a graphical user interface. Instead, they used the command line, which is still available as Windows PowerShell, for example. For each action, whether the opening of a data file, the navigation of a file system, or the launch of a program, users had to know the correct command and enter it manually. Only once computers entered our home did simpler user interfaces became the norm, with Microsoft (Windows) and Apple (macOS) now leading the market.