When we talked about pinning the tail on the donkey we said that coding consists in telling instructions, the problem is that the computer does not speak our language.
So what language does computer speak? Several I would say.
The core of the computer, CPU (Central Processing Unit) uses machine language that is a small set of simple instructions, written as numbers (binary numbers eg: 00101001).
Assembly is another language, basically it matches each machine language instruction with a short word, making it more understandable for a human (eg: MOV, SUM).
Low level language, high level language
Assembly is more understandable but yet very difficult to use, even for an expert programmer as to perform very complex operations, it is necessary to combine many of these simple instructions, sometimes reaching a very high level of complexity.
That’s because this language is very close to the inner workings of the processor. So it is called low level language, but please do not be fooled by the name, it has no negative or dismissive meaning on the contrary low level languages are very important and hard to master.
The solution that computer scientists figured out was to invent another language (actually more than one) that could be even easier to use. These new languages are known as high level languages and they are closer to human language.
Such languages have more instructions and they are even more complex or as we usually say more powerful. That means that a single instruction in an high level language corresponds to many instructions in a lower one.
Let’s consider a powerful word: multiply.
Why is it powerful? Why is it an higher level instruction?
5 x 8 = 5 + 5 + 5 + 5 + 5 + 5 + 5 + 5
Multiplication means repeating several times the same addition. That’s actually what a processor would do: loop several times through a series of additions (repeat and sum are two basic low level operations).
The use of higher level languages is allowed by special programs called translators (intepreters and compilers) that take higher level instructions and turn them into lower ones.
Applying multiple levels of translation allows more layers of programming languages that can get near to human language and make programming even easier and powerful. But that is for another post.