Sentences have been matched to an image that will help students make meaning of the difficult vocabulary found in Domain 2, Classification of Animals in the Core Knowledge curriculum. Vocabulary words and definitions are sold separately. You don't necessarily need both the images/sentence cards and the vocab. cards/definitions. It depends on the focus that you have for teaching vocabulary.
If you do choose to purchase both for each domain, you could have students match the images and sentences to the vocabulary cards with definitions. This can be done in a center. Or, you could have your students play memory by matching the sentence/image card with the word/definition card. One or the other could also be placed in a pocket chart and then each student handed one or the other and asked to match the partner card in the pocket chart.