The term "nurse" could refer to a licensed practical nurse, a registered nurse or an advanced practice nurse, while a vet tech could be a veterinary technologist or a veterinary technician. Each of these occupations has different educational requirements as well as varying license or certification opportunities and requirements. These factors affect salaries in each occupation.

Registered Nurses

Registered nurses provide, plan, direct and coordinate patient care. Initial education could include an associate degree, nursing diploma or bachelor’s degree, according to the U.S. Bureau of Labor Statistics. All states require a license, and although certification is optional, it may be preferred or required by employers. Hospitals are the most common work setting for RNs, reports the BLS. The average annual salary for RNs in 2012 was $67,930. California was the best-paying state, with an average salary of $94,120.

Licensed Practical Nurses

Licensed practical and licensed vocational nurses -- titles differ in various states -- work under the supervision of an RN or doctor to provide direct patient care. Educated in one-year postsecondary programs, they must be licensed but do not have the option of certification. The average annual salary for LVNs in 2012 was $42,400, according to the BLS, and the most common work setting was skilled nursing facilities, where LPNs earned $43,570. The top-paying work setting, however, was junior colleges, with an average annual salary of $49,320. LPNs in Connecticut had the highest annual salary, at $53,560.

Advanced Practice

Advanced practice nurses earn much more than the average RN. They also have more education, as a minimum of a master’s degree is required for this group, and certification is required in most states. APRNs have an expanded scope of practice; they can make a medical diagnosis, order lab and other diagnostic tests and prescribe medicine. Nurse midwives provide gynecologic and obstetric care and earned $91,070 in 2012, according to the BLS. Nurse practitioners, who provide primary care, earned $91,450. Nurse anesthetists, who administer anesthesia and manage pain, were the top earners, at $154,390.

Two Types of Vet Techs

Veterinary technicians are usually educated at the associate degree level, according to the BLS. They provide basic support to a veterinarian and perform tasks such as laboratory tests. Veterinary technologists usually have a bachelor’s degree in the field. Many work in veterinary research rather than private practice -- the common work setting for a veterinary technician -- where they administer medications, prepare tissue samples and document information. Both types of vet techs are usually registered, licensed or certified and must take an exam to practice, states the BLS. The BLS combines salary data for these occupations and reports that the average annual salary in 2012 was $31,470. Vet techs who worked for the federal executive branch earned $48,370. Alaska was the highest-paying state, with an average annual salary of $39,380.