What is semi-formal letter?

A semi-formal letter is a type of correspondence that strikes a balance between formal and informal styles. It is typically used for communication with acquaintances, colleagues, or clients where a friendly yet respectful tone is appropriate. The structure includes a greeting, body, and closing, but allows for a more conversational language than a strictly formal letter. Common contexts for semi-formal letters include invitations, thank-you notes, or requests for information.