Operating System Interfaces

They way an object interfaces with another is very important. If the interfacing object is provided with certain instructions or procedural guesses, then it stands a better chance of effectively interfacing with the other object. There are two main types of interfaces in operating systems, a user interface and an application interface.

User Interfaces

The interface between the user and the computer is a very important part of the operating system. Depending on the user interface used, the way an individual interacts with the computer is radically changed. Based on these differing user interfaces, we can categorize operating systems into three types.

The first type is known as a terminal system.  These operating systems work primarily through text entered input and provide no graphics to users.  These systems use a command language to tell the computer what actions to perform.  Terminal based systems were some of the first operating systems design and used on computers; UNIX and early flavors of Linux relied heavily on this interface.  Many computer users like this system for its speed, as you never need to remove your hands from the keyboard to reach for a pointing device such as a mouse.

The more modern type of operating system is known as a GUI system.  GUI stands for Graphical User Interface.  These systems allow a user to use a mouse or some other pointer device and click, select, drag, and manipulate objects in a more graphical sense.  Windows XP is a prime example of a GUI system.  Most OS developers have moved towards this type of environment due to its ease of use.  By making things simpler and graphical, more people are able to effectively use a computer without having to be a computer expert or poses the understanding of a special command language.

The third type of operating system is a hybrid of the previous two.  The use of each flavor of user interface, GUI or terminal, can vary in proportionality. For example, today’s versions of Linux provide a GUI for users while most of the power still lies in the terminal based input and output of information.  Mac OS X on the other hand is primarily a GUI system, however it possesses terminal abilities that are often employed by power computer users or developers.

Application Interfaces

In addition to providing User Interface methods, an operating system provides an interface for applications known as an API.  API, or application program interface, is an interface provided for applications that allow for effective communication between applications, the operating system, and the hardware. The API plays an important part in the hardware abstraction of the operating system. The API contains the definitions and instructions that tell an application how to talk to the operating system. This allows the operating system to then pass these instructions on to the kernel and provide access to hardware resources.