If a code has poor quality, it is very difficult for everyone to understand what the code is supposed to do. Good quality code should have good reliability, robustness, usability, portability, maintainability and readability. Reliability means ensuring that the code will work each time it is run without producing errors and ensuring that its operation is consistent. Software that has good reliability would mean that it contains no errors and works properly. Robustness is similar to reliability, but robustness is about making sure the code is able to handle user errors and a good quality program should produce an indicator telling the user that there is had an error instead of crashing, for example creating a message saying "It was an error". please try again” compared to programs where they would not provide any indication and the user might not know there is an error. Usability means how easy the code is to understand and can the code be used by other people. Portability means ensuring that the code can be used on as many different operating systems as possible, for example Java is a programming language that can be used on different devices and different operating systems thanks to the JVM (Java Virtual Machine) which compiles the Java code. then interrupts it differently depending on the operating system