Autor: Alexander Eichhorn

Operating Systems - Overview

The operating system (OS) is the central system software that manages all computer hardware resources.

It provides a uniform interface and common services necessary to run application software. For example, an operating system grants access to the CPU and allocates memory to every program. It monitors all running software and can withdraw resources when required, even without the consent of an application. The operating system also ensures that programs do not interfere with each other and that data is reliably and securely stored.

All modern operating systems used on desktop, laptop and server computers as well as the ones on smartphones are multi-tasking systems, meaning they can concurrently execute multiple programs at once. When the CPU hardware features multiple cores programs can truely execute in parallel. All desktop-class systems implement the concept of a user with a unique identity and are thus able to manage multiple user accounts. A typical mobile OS for smartphones and tablets lacks this feature.

Mac OS X

OSX is a series of operating systems developed by Apple Inc. for their desktop and laptop computers. OSX is a UNIX operating system with a graphical user interface that specifically targets design and creative workflows. Some parts of OSX such as it's kernel are open-source, but most software is proprietary and closed.  Apple guarantees to ship updates for the latest two major revisions of OSX. Software and security updates are published infrequently. Some 3rd party security products exist.


Windows is an OS family from Microsoft Corporation for personal computers (PC) with an Intel architecture CPU. Windows main use cases are office workflows in small to large businesses, but also gaming and recreational use by home users. Microsoft publishes regular software and security updates and also defines an exact end-of-life date for every version of Windows after which support ends. Many 3rd party security products exist.


Linux is a UNIX operating system developed as a collection of open-source projects by multiple independent individuals and companies. Linux is mainly a server operating system, but its versatility allows to run different graphical user interfaces as well. Linux main user group are programmers, researchers and businesses who run large-scale Internet operations. Software for Linux is either directly available as source code from authors or gets bundled as binary packages into different distributions. Software and security updates are published very frequent.


iOS (iPhone OS) is a mobile operating system family developed by Apple Inc for its line of smartphone and tablet products. iOS exclusively runs on Apple hardware and is limited to a touch-based user inteface. Apple tightly controls 3rd party software access to hardware and OS functionality and allows only approved application software to be installed on the device. Apple publishes software and security updates infrequently. Apple's mobile devices include a sophisticated hardware and software security architecture, that helps protect data and user credentials and simplifies integration into corporate environments. A mobile device management framework allows to remotely control corporate devices, provides single-sing-on and isolates personal data from corporate data.


Android is a mobile operating system family developed by Google Inc for smartphones and tablets and released as open-source. It is based on the Linux kernel and features a touch-based user interface. Device manufactures can integrate a stock Android version with proprietary software on their devices. Software and security updates also fall under the  responsibility of device manufacturers. Unfortunately many manufacturers have no commercial interest in providing updates, so most Android devices are never updated after release and security vulnerabilities remain widely unpatched.

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