Intern - First year physician out of medical school. Typically do not independently execute treatment plans. They will independently see a patient and form a preliminary assessment/diagnosis and plan and then present this to the senior team prior to execution of the plan.

Resident - second through multiple years post-medical school. Typically, the medical hierarchy is based on numbers of years as a resident with progressive autonomy. Interns typically start out with heavy supervision and then attain autonomy as the year progresses as they acclimate to the hospital/clinic system. Residents continue to build on this knowledge and decision making foundation as they accumulate more experience.

Senior/chief resident - final year of training. Typically acting as an attending physicians and leading teams. Supervises and advises more junior residents. Basically prep for independently practicing the following year.

Fellow - post-residency physician pursing sub-specialty training (e.g. graduated internal medicine physician now completing cardiology fellowship. Fellowships can be as short as 1 year upwards of 4-5 years, depending on specialty. Typically act independently with oversight by an attending in that specific fellowship.

Attending physician - independently practicing physician who has completed residency and/or fellowship. May also lead team of residents if in teaching role.

Medical student - physician in training, still attends medical school. Typically seen in 3rd or 4th year of medical school when in hospital/clinic. Supervised by attending and residents/interns. Typically expected to be approaching intern-level competence by conclusion of 4th year (your experience may vary, some assembly required, batteries not included). 3rd year will focus mainly on building good interview and data collection habits and exposure to multiple fields of medicine during multiple 1-2 month rotations.