Compilation — Computing, 11–13
People write programs in languages designed for humans, while processors need much more precise instructions. A compiler translates the first into another form that the computer can run or prepare to run.
From code to a runnable program
When you write code, you are giving instructions in a language made to be readable by people. Compilation changes that text into lower-level instructions, checks some rules, and produces something the computer can use.
Why translate code
Processors are fast but unforgiving: a small ambiguity can stop an instruction from working. Human-friendly languages let you name ideas and organise a solution, while compilation builds the exact form needed by a particular computer or system.
A tiny translation
Suppose you write `score = 2 + 3`. The compiler checks that the names and symbols are allowed, works out that the addition gives 5, and creates instructions for storing that result; if you write an unknown symbol, it reports an error instead.
Compilation is not proofreading everything
It is reasonable to expect a program that compiles to be correct, because the compiler has already rejected some mistakes. But it mainly checks whether the code follows the language’s rules; it cannot know that you meant 5 instead of 50.
Why some errors appear before running
When an app or game is built, compilation can catch missing punctuation, unknown names, and other rule-breaking code before anyone opens it. This saves time, though the finished program still needs tests for mistakes in its behaviour.
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