A tier is a level or rank in a system where things are organized by quality, importance, or position. Think of a wedding cake with layers stacked on top of each other: each layer is a tier, and the tiers get smaller as you go up.

In everyday use, tier often describes rankings or categories. A video game might have top-tier characters that are the most powerful, while low-tier characters are weaker. Schools sometimes organize spelling competitions in tiers based on difficulty, with beginning spellers in one tier and advanced spellers in another. Sports leagues often have multiple tiers: professional teams play in the top tier, while amateur or developing teams play in lower tiers.

Tiers help us understand where something fits in a hierarchy. When something is described as first-tier or second-tier, that tells you its relative quality or importance. A multi-tiered system, like a country's court system, has several levels of organization.

You'll also see the word used for physical structures: tiered seating in an auditorium gives everyone a good view, with each row slightly higher than the one in front. Stadium seating works the same way, with tiers of seats rising up from the field.