Explain the term "first-class mail."

First-class mail encompasses various types of mail that are prioritized for efficient and prompt delivery, specifically targeting letters and small packages. This classification is significant as it ensures that these items receive expedited handling through the postal system, leading to faster delivery times compared to other mail services.

In the context of postal services, first-class mail can include standard letters, postcards, and lightweight parcels, making it a versatile choice for sending both personal and business correspondence. The priority given to first-class mail facilitates its delivery within a designated timeframe, which is typically 1 to 3 business days, depending on the destination. This service is advantageous for time-sensitive communications, making it the preferred option for many senders.

Other classifications of mail, such as freight services, typically deal with much larger bulk shipments and do not offer the same delivery speed or type of items as first-class mail. Similarly, the notion that first-class mail is processed last or is limited to legal documents is inaccurate, as those scenarios pertain to entirely different classifications or contexts of mailing services.