What are the kinds of social letters and their meaning?

There are sic different types of social letters that can be written. A thank you letter expresses an appreciation of something that was given. A sympathy letter offers condolences for a sad event. A congratulations letter is for when something good happens to a family member or any other person. An apology letter is offering sincerity. A romance letter is very personal and expresses affection. A personal news letter shares updates and thoughts of what is happening in one's life.