Perhaps the biggest reason that I write is to convey information. Humans have been using writing to convey information to one another for thousands and thousands of years, which we still do today. I may write someone a card to express my love for someone, or I may write a resume in order to tell a potential employer about who I am. Generally however, I write my signature on pieces of paper to convey that something has my approval or that I made a purchase somewhere. Writing has evolved a lot over the past thousands of years, new languages have been created and alphabets have been invented, but at the end of the day many people write to do the same thing that our ancient ancestors did, to convey information.