Conclusion

 

Table: Overview of Computer and User Interface History

	CPU	Language	Interface
1st CG	Vacuum Tubes	Machine Language	Front Panel
2nd CG	Transistors	Assembler	Punch Cards
3rd CG	IC	FORTRAN	Terminals
4th CG	LSIC	C and C++	Menus and GUIs

The development of interactive languages began with the introduction of time-sharing systems in the third computer generation. Decreasing prices and increasing computer speed were the decisive factors which made it possible to concentrate on user interfaces. While early systems were command-based, the majority of systems makes use of graphical user interfaces today. The desktop metaphor has become the most popular user interface due to its ease of use.
While early users of computer systems were also their creators and programmers, there is a clear distinction between machine manufacturers, programmers, and users today (although a machine manufacturer may also code programs and use programs coded by others; this case, however, is regarded as an exception).
Regarding programming languages, a shift from machine code to high-level languages has taken place, including directive, functional, descriptive, logical, and object-oriented languages. Thus, not only has the user interface become easier to use, but programmers deal with more or less understandable code instead of machine language. A brief summary of the developments described in this section is shown in table 1.