Punctuation is the system of signs or symbols given to a reader to show how a sentence is constructed and how it should be read.
Sentences are the building blocks used to construct written accounts. They are complete statements. Punctuation shows how the sentence should be read and makes the meaning clear.
Every sentence should include, at least, a capital letter at the start a full stop, exclamation mark or question mark at the end. This basic system indicates that the sentence is complete.