The Jack Russell Terrier is a small, energetic, and athletic dog breed known for its high energy and intelligence. They have a compact and muscular build, with a short and smooth coat that is typically white with black or tan markings. Jack Russells have a distinctive head shape with triangular ears that fold forward and a keen and alert expression. They are highly energetic and require plenty of exercise and mental stimulation to stay happy and healthy. Jack Russells are known for their strong hunting instincts and can be prone to digging and chasing small prey. They are also loyal and affectionate with their families and can make great companions for active individuals or families with older children. However, their high energy and independent nature require an experienced and patient owner who is willing to provide them with proper training, socialization, and stimulation.