What purpose does a thank-you note serve?

A thank-you note primarily serves to express appreciation to another party. This type of note is personal and conveys gratitude for a specific action, gift, or gesture that someone has provided. By acknowledging another person's kindness or effort, a thank-you note strengthens relationships and fosters goodwill. It can also indicate that the recipient is valued and appreciated, which is essential in both personal and professional interactions.

In contrast, the other options mention purposes that are quite different in nature. Extending formal invitations typically involves a more detailed communication format focused on logistics and details of events, while announcing upcoming events is informative and emphasizes sharing news rather than expressing gratitude. Documenting a transaction pertains to keeping records and is more about formal agreements than personal appreciation. Thus, the essence of a thank-you note lies specifically in its role of conveying thanks and recognition.