Calico describes a coat, not a breed: white with patches of orange and black, or gray and cream in the softer dilute version. Most calicos you'll meet are domestic shorthairs, medium-sized cats of roughly 6 to 12 pounds who can live 12 to 18 years indoors. Nearly all are female, thanks to the way the color gene is carried.
Because the pattern says nothing about ancestry, care follows ordinary house-cat basics: a balanced diet, vaccines, dental care and daily play. Shedding is moderate, so a weekly brushing handles most shorthairs, while longhaired mixes need more. Personality ranges from shy to bold, and the "tortitude" reputation isn't backed by research, so spend time with a cat before deciding.