カバー (kabā) means “cover” | MotiTan Japanese Dictionary

More examples

雨の日は自転車にカバーを掛けます。ame no hi wa ji ten sha ni ka bā o ka ke ma su

I put a cover on my bicycle on rainy days.

Refers to an outer layer that fits over an object and protects or conceals it.

ケースkēsu: A container or holder that encloses an object for storage or protection.

本や機器などを覆い、汚れや傷から守るために取り付けるもの。hon ya ki ki na do o ō i yogo re ya kizu ka ra mamo ru ta me ni to ri tsu ke ru mo no

The Japanese noun カバー (kabā, "cover") comes from English cover, ultimately related to Old French covrir, "to cover."

A phone cover in Japanese is a カバー (kabā), while a small container-like case is often called ケース (kēsu), so the two terms can overlap.