In the Workplace (职场): This is one of the most common uses. Companies have clear internal ranking systems. For example, in Chinese tech giants, you'll hear about “P-levels” for professionals (P级) and “M-levels” for managers (M级). A person's 级别 determines their salary, bonuses, responsibilities, and authority.
In Government (政府): The civil service system is built on a complex and rigid system of 级别. A person's official rank (e.g., 科长 kězhǎng, 处长 chùzhǎng) is their 级别, and it is of utmost importance.
In Gaming & Entertainment (游戏与娱乐): In the world of online gaming, 级别 is a core concept. Players are always trying to “level up” (升级, shēngjí) to a higher 级别. The word is also used for item grades, difficulty settings, and character ranks.
In Products & Services (产品与服务): Companies use 级别 to classify their offerings. This includes hotel room types (e.g., standard, deluxe, suite), VIP membership tiers (e.g., silver, gold, platinum), and the quality grade of products like tea or jade.