A "doctor" can refer to two distinct groups: medical practitioners (like physicians, dentists, or veterinarians) who have earned a professional degree and are licensed to practice, and individuals who have earned a doctoral degree, often a PhD, from a university. In a medical context, "doctor" is generally used to refer to a medical practitioner, while in academic contexts, it often refers to a person with a doctorate. 

Elaboration:

Medical Practitioners:

In the medical field, a doctor is a healthcare professional who practices medicine, diagnoses and treats illnesses, and may perform surgeries or prescribe medications, according to Collins Dictionary. Examples of medical doctors include physicians, surgeons, dentists, veterinarians, and psychiatrists. 

Academic Title:

The term "doctor" also refers to a person who has earned a doctoral degree, such as a PhD, which signifies the highest academic degree in a particular field of study, according to Wikipedia. 

"Dr." as an Abbreviation:

The abbreviation "Dr." is commonly used to refer to both medical practitioners and individuals with a doctorate, although the specific context often clarifies which type of "doctor" is being referr ed to. 😄🙏🎂😁🍬