A contextual example is an event, object, or situation that can be understood only by reference to its immediate surroundings, or context. For example, a small child may ask their parent for a drink of water while they are playing outside on a hot day. In this context, the child is thirsty and is asking for something to drink. However, if the child were to ask for a drink of water while they were sitting in a classroom, the context would be different. In this case, the child may be thirsty, but they are also likely to be thirsty because they are required to sit still for a long period of time.
Contextual examples are important because they help to explain the meaning of words and phrases. They can also be used to provide evidence for an argument or claim.