"Fourth-Class" refers to a category of service or classification, often used in various contexts such as education, transportation, or postal services. In the context of education, it may denote a specific grade level, typically for younger students, focusing on foundational skills in subjects like reading, writing, and mathematics. In postal services, "Fourth-Class" can refer to a type of mail service that is generally slower and less expensive than first-class options. This classification is often used for bulk mail, such as catalogs or promotional materials, allowing businesses to send large quantities of items at a reduced rate.