Carnivores mainly or exclusively live on a diet of animal tissue. They can be predators or scavengers or both.
Herbivores mainly or exclusively eat plant matter.
Omnivores eat both.
Humans (Homo sapiens) are certainly capable of consuming both animal and plant foods. Whether we are morphologically and physiologically more adapted to consume one or the other, however, is something we will explore here. See for yourself whether we have more traits in common with carnivores, omnivores, or herbivores.
Figure 1 illustrates that diets are often more varied and that it is hard to draw sharp lines. For example, we here use the term herbivore to describe an animal whose diet mainly or entirely consists of plant matter; however, within that group of herbivores is a huge variety of preferred foods. While some animals nibble on soft fruits, others almost exclusively eat grass or mature leaves.
Similarly, the term omnivore encompasses animals that truly eat both animals and plant foods in roughly equal amounts, but also those who mainly live on fruits, nuts, and seeds, and only occasionally eat small animals if the opportunity presents itself.
Nature is complex, and there are exceptions to every rule. One excellent example is the panda bear. Although pandas are phylogenetically and morphologically in the order Carnivora, they certainly have a herbivorous diet.
Fig. 1: The spectrum of mammalian diets .
 Hiiemae, Karen M. “Feeding in Mammals”. In: Schwenk, Kurt, ed. Feeding: form, function and evolution in tetrapod vertebrates. Academic Press, 2000.