On a related note, while programmers do not need to know where in memory they are storing their data, they need to be aware of how much they are storing. Depending on the programming language, the programmer may be responsible for "garbage collection," or giving memory back to the computer when it's no longer used by the program. If this is not done properly, this may result in a "memory leak," which means the program takes up more and more memory as time passes. This causes problems as it prevents other programs from working correctly due to limited resources.