The given graph illustrates the major writing systems which people use in the whole world.
Overall, there are 5 main writing systems. All these systems have their own algorithms for writing and examples.
According to the diagram, the first method is a Logographic, which means that 1 character equals to 1 world. For example, it can be Chinese. Although, the same system of writing can be used by other languages in spoken form (Chinese and Japanese). The second one is an Abjad. The main difference is that 1 character equals to 1 consonant sound (Arabic). Another system of writing is an Abjuda, in which 1 character equal to 1 constant and 1 vowel. For instance, it can be Indian Devanagari. Also there are 2 last but not least writing system: Alphabetic and Syllabic. In the Alphabetic method 1 character equals to 1 sound (vowel or consonant). It can be English. However, in that type of writing system exact match of spelling and pronunciation are not always possible. And the last one is a Syllabic type, where 1 character equals to 1 syllable (Japanese Kana).