An operating system connects hardware and software, managing hardware resources and allowing the processor to run software and perform tasks. The main types are Windows, Mac OS, Linux, and DOS. Windows is the most popular as it comes preinstalled on most computers sold and has a graphical user interface (GUI) allowing interaction through windows, icons, menus and pointers. It supports many types of hardware and allows security through passwords but the code cannot be modified. Linux also has a GUI but is open source, allowing users to customize it, though it supports fewer types of hardware. Mac OS only runs on Apple computers and also has a GUI, but unlike Linux, its code cannot be modified.

1. Operating Systems
An operating system is the program that connects the hardware with the software
and the user. The OS manages and controls the hardware to store data and gives the
processor instructions to run software and perform other tasks.
There are 4 main types of operating systems, which are Windows, Mac OS, Linux and
DOS.
Windows is the most popular operating software, because it is on the most
computers sold. There are many different versions of Windows, the newest being 8.1.
Windows 0perating system is a GUI (graphical user interface). GUIs are made up of
WIMP. This is Windows, Icons, Menus and Pointers. Windows was originally made
to go on top of DOS. Windows is fairly secure, it allows you to set passwords and
users to prevent unauthorised people accessing certain files. Windows allows
peripherals to be added such as removable memory or other devices both input and
output. Windows generally allows more types of removable media to connect than
other operating systems such as Mac OS. Windows has explorer as their file
manager. This provides a GUI for accessing files and navigating around the desktop.
Device drivers are available for Windows that help hardware be recognised when it is
plugged in.
DOS is a command line driven operating system. DOS stands for Disk Operating
System. You have to enter commands to do anything on the computer, which isn’t
very good because you have to know exactly what to type in to the computer. It isn’t
really used anymore, but it was a similar make up to BIOS. Years ago the DOS would
load up, and you would enter a command to then launch the GUI operating system.
DOS doesn’t allow connectivity of peripherals, so there is no peripheral management.
It only runs from the HDD, and outputs onto the screen. You can type in commands
with a keyboard, but you can’t use a mouse. DOS doesn’t really have any security, as
it was written before viruses were around, and usually another OS is put on the top of
it that has security. DOS doesn’t have a system in place for exploring files like
Windows but you can access files by typing in a command. DOS doesn’t support the
connecting of devices, so there are no device drivers.
Linux is also a GUI system, but it is open source, so you can rewrite the codes to
customise it. The Linux OS works in a similar way to Windows, but it is simpler
because it has fewer applications inside it. Because you can alter the codes, you can
manage the machine yourself rather than it being down by the OS. Linux manages
peripherals similarly to Windows, but doesn’t recognise as many. Linux is fairly
secure, because you can alter the codes it makes it hard for malware to attach itself to
the computer because each version of Linux is unique. Linux has a system similar to
Windows for browsing files on the computer. The device drivers on Linux are easily
downloaded from the device or the internet.
Mac OS is similar to Windows and Linux, but you cannot alter the code for it. Mac
OS only works on Mac computers, so you have to buy a Mac if you want that OS. Mac
OS is a family system, because there are many different versions of it. Peripherals
generally have to be Mac as well, such as external hard drives, to be recognised by the
OS. It is fairly secure, but as you can’t alter the codes for it, it can be infected by

2. malware. It has a system called the Finder which allows you to access files and
applications on the computer. There are device drivers available but most of the time
they have to be Mac to be recognised on the system.