SYSTEM SOFTWARE

GUI (Graphical User Interface): The UI (User Interface) is the thing the user interacts with the GUI is how you see it. 

All operating systems have a COMMAND LINE INTERFACE that allows the user to 

input direct commands to use the operating system functions.

Most operating systems allow the user to make 
adjustments to the settings, for example: 
• Screen resolution 
• Keyboard layout 
• Sound settings 
• Start up options 

• The operating system is loaded from disk into 
RAM on the typical desktop or laptop computer. 
• For devices running embedded systems the 
operating system is stored on ROM or in flash 
memory. 
• Software stored in this way is called firmware. 
• Firmware is typically the set of small programs 
used to control an electronic device. 
• Larger computers also have firmware in ROM to 
take care of boot up.

Operating systems also have supporting software to manage 
various aspects of the system: 
• Utility software 
– is often loaded with the operating system 
– comes as small-scale programs used to carry out simple 
maintenance tasks. 
• Security 
– Anti-virus software to detect and remove viruses that could 
damage the data on the computer; 
– Anti-spyware to detect and remove spyware such as a Trojan 
that logs key strokes to steal passwords and other sensitive data; 
– Firewalls that restrict incoming and outgoing access to certain 
network addresses. 

Maintenance: Disk organisation tools allow 
formatting and management of files on disks, for 
example: 
– Disk defragmenters: As files are deleted and added, 
the data gets spread around the disk, leaving gaps. The 
defragmenter moves the files to put all the free space 
together to improve access speeds. 
– Other utilities include: 
– Archive 
– Backup 
– Data compression 
– Disk cleaners 
– Network utilities 

Most operating systems have software to help them operate at peak potential. 

Most operating systems allow the user to customise the UI and change certain 

things.

DEVELOPMENT SOFTWARE

Compilers: Translate high-level code by the programmer into machine language for the computer to process.

Interpreters: Do exactly the same as Compilers but they translate one line at a 

time and execute as they translate.

Assemblers: Translate assembly language into machine instructions. Instead of 

using binary they use mnemonics to represent the code.

Linkers are used to connect together sub programs to create larger programs. 
Often programs are made up from sub programs written using different tools and 

languages. 

Linker: is used to combine all of these separate 
modules of code to ensure they will work together. 

NIC

NIC stands for Network Interface Controller.

LAN ADVANTAGES

A local network to share data.

DISADVANTAGES 

The admin can block certain things.