The expansive nature of public health allows for many areas of speciality. Because of this, most colleges and universities that offer a degree in public health will have concentrations that students can declare. By declaring a concentration, the student will focus his or her course work in a specialty area of public health and will gain the skills needed for a career within that specialization. PublicHealthDegrees.org has compiled a list of the top public health specialities in the field that translate into public health program concentrations.
Two additional things to note is that colleges and universities may combine similar specialties into one overarching concentration (ex: Community Health and Health Promotion) and that a school may use different names for their concentrations (ex: Industrial Hygiene instead of Occupational Health).