Wolves are members of the family Canidae, the same biological family that includes domestic dogs, foxes, coyotes, jackals, and other canids. The gray wolf (Canis lupus) is the most widely recognized wolf species, but wolves are not limited to a single population or region. Different wolf populations have adapted to an impressive variety of environments across the Northern Hemisphere.

Wolves are social, intelligent, and highly adaptable carnivores. They are capable of living in forests, mountains, tundra, grasslands, deserts, and other environments, depending on the population. Their physical characteristics and behavior can vary considerably between populations as they adapt to local conditions.

A wolf's life is strongly connected to its social relationships and its environment. Wolves commonly live in family-based groups called packs, where individuals cooperate in activities such as raising young, defending territory, and obtaining food. Their ability to communicate and work together is one of the defining characteristics of wolf society.

Although wolves are often portrayed simply as dangerous predators, their lives are considerably more complex. Understanding what a wolf actually is—and how it lives—is the first step toward understanding the species as a whole.