Writing is a fascinating thing and although we usually don't think much about it, it is one of the major inventions of human communication. It allows us to communicate not over great distances in space – such as this article reaching you – but also to communicate over great distances of time. It enables us to transport information over several generations and in a far greater quantity than if all information had to be memorised and dilivered through oral tradition.
But writing isn't just one thing. There are several different alphabets – this text is written in the modern latin alphabet, but it is far from the only one in existence. In fact, it is not even the only system of writing.
Another system of writing is called logographic and is represented by systems such as the egyptian hieroglyps or the chinese Han characters. In such a system each character has a specific meaning rather than a phonetic value. This enables the writing to be read by people who would not understand each other's speach, but because the writing transports concepts and meanings in it's symbols rather than sounds, people who speak different languages can all communicate using the same writing. In a pre-modern China, this was extremely useful: The country was extremely large and people from one end of the country would have little chance to hear the speach of someone from the other end of the country and so would have rather different ways of speaking. But the Han Characters did not represent the spoken sounds, simply the meaning.
Logographic writing systems have some drawbacks however: For one, they require a very large number of characters, since everything has to have it's own character and that makes it very difficult to learn to read these writing systems since they are almost a second language. And secondly the characters do not give any indication of how a word is supposed to be pronounced, so if you do not know a character, you have to show it to someone to get an answer for what it means.
So that leads us to another type of alphabet: The kind that represents sounds. It has the advantage that it can be used to spell out sounds and so will give you an idea what the word you read sounds like. It also requires far fewer characters, which can be reduced even further if you accept a certain ambiguity of sounds. For example, if all the sounds that modern english represent with an A had to have their own letter there would be quite a few more than the single character we see today. But allowing one character to hold all these similar-sounding sounds rather than make a character for each of them makes writing simpler to learn.
That isn't the end though, for there are writing systems who do a little bit of both and do a sort of rebus writing where they have a relatively small number of logographic characters which are known by everyone and then they are strung together to create other words with the same sounds. These can be interspersed with actual logographic characters that represent their 'concept'.
There is so much to be learned about writing and I can only encourage anyone who's interested to learn more to dive into it; it is truly fascinating.
Scientifics are slightly geeky additions that have been with us since the eagle has known how to fly. Okay, not that long, but it's a nifty category that separates it from the usual ramble of articles.