High & Low Level Languages (CIE IGCSE Computer Science)

Low Level Languages

• Low Level Languages are languages that sit close to a computer’s instruction set. These are basic instructions that the CPU will understand 
• For instance an assembly language​ which allows programmers to focus on programming simple commands, which in turn is converted into machine code This element is needed for the core hardware to be able to work with the software
• These languages are written for specific processors to ensure they embed the correct machine architecture
• Assembly Language - The code is written using mnemonics, abbreviated text commands such as LDA (Load), STO(Store) Using this language programmers can write human-readable programs that correspond almost exactly to machine code.
• Machine code – is at the hardware level and is written in binary (1’s and 0’s)
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Advantages	Disadvantages
It gives programmers complete control over the system components so it can control hardware components.	Difficult to write and understand
Efficient code can be written for the processor so it will occupy less memory and execute faster	Machine dependent and cannot be added to different specification machines
They provide direct manipulation of hardware which means it will be more efficient	More prone to errors
Communicates directly with hardware	Knowledge of computer architecture is key to program effectively

High Level Languages

• High Level Languages are programming languages which use English-like statements which allow users to program with easy to use code, allow for clear debugging and once programs are created they become easier to maintain
• High level languages were needed more due to the development of processor speeds and memory capacity increasing
• Examples of these languages are Python, C#, Java etc​
  
  

Advantages	Disadvantages
It is easier to read and write and the programmer is less likely to make mistakes	The user is not able to directly manipulate the hardware
It is easier to debug so it will save time	Needs to be translated to machine code before running
The code is portable so can be used on any computer	The program may be less efficient
One line of code can perform multiple commands