concrete example; specific instance
Used when giving a clear, real-world illustration of an abstract idea or rule.
An abstract explanation alone is hard to understand, so please give a concrete example.
具体例 emphasizes a concrete, detailed example used to clarify an abstract point, while 一例 simply means 'one example' without that emphasis on concreteness.
Compound of 具体 (concrete, tangible) and 例 (example).