This photo is labeled as 'Happy Holly' the short-haired Jack Russell Terrier --- (Though, if you ask me, this is not a pure Jack Russell. It clearly looks mixed with Cairn Terrier or even a Westie, based on the shorter legs & smaller, pointier ears.
Havanese dogs are often considered the perfect pets. The Havanese is a pure breed toy dog which is intelligent and has a gentle disposition which makes it a perfect choice for most families. If you've seen pictures of Havanese puppies, you'll see.