Key difference: The difference between a police officer and a sheriff is pertaining to their area of jurisdiction. A sheriff is elected by the citizens and he maintains law and order in his county. A cop is a government official, who looks after the law enforcement in a specific city, municipality, town or village.

Police officers and sheriffs are both peace officers who risk their lives for the safety and security of their communities. They both belong to the law enforcement organization. The main goal of this organization is to promote public safety and the welfare of the state, through education, regular patrols and crime investigation. Although police officers and sheriffs have similar duties, some differences set them apart.

A sheriff is a legal officer with a responsibility for maintaining law and order in a county. The term ‘Sheriff’ comes from an old English concept, wherein it was referred to a royal officer who was responsible for keeping peace throughout the county on behalf of the king. Nearly, all the countries in United Kingdom had sheriffs, who were required to do rounds for the king.

Later, this concept of sheriffs’ was adopted by the United States, which became a part of their law enforcement program. The word ‘sheriff’ is derived from the term "shire reeve". The office of a sheriff is called as ‘Shrievalty’.

In practice, the specific combination of legal, political and ceremonial duties of a sheriff vary greatly from country to country. In Scotland, sheriffs act as court judges. They conduct sessions in court regarding trails, bails, etc. and place judgment on the cases. The sheriff have different responsibilities in different countries, which are required according to the given law program of a country. There are ceremonial positions for sheriffs in countries like England, Wales and India. In countries like Ireland, Australia, and Canada, the sheriffs are considered as legal administrative officers, who are considered similar to bailiffs; their duties are expanded or reduced regarding certain provinces in a country.

The sheriff is generally considered to be the highest law enforcement officer of a county. His office is called as ‘marshal’. He is most often considered as a county official, who serves as the arm of the county court. The sheriff's authority may be more recognized, as the people of the county elect the sheriff. In the United States, the scope of a sheriff varies with the states and counties. In Virginia, sheriff's office serves as the arm of the city court and jail for people. The sheriffs perform court duties, which may include functions such as administering the county or city jail, providing courtroom security and prisoner transportation, serving warrants and serving process. In urban areas, a sheriff may be restricted to perform such duties. Sheriffs and their deputies may be considered as the principal police force.

Police Officers, in general, are referred to as ‘Cops’. They are warranted employees of the police force. In the United States, "officer" is the formal name of the lowest police rank.

According to Wikipedia, the general duty of a police officer is to capture the criminals, prevent and detect crime, and maintain public order. Police officers are usually sworn to an oath. They have the power to arrest people and detain them for a limited time, along with other responsibilities. Some police officers are also trained in special duties, such as counter-terrorism, surveillance, child protection, VIP protection, and investigation techniques into major crime, including fraud, rape, murder and drug trafficking.

The police force first originated in 1700s to enforce law and policy for the people. One of the first truly organized police forces was the Metropolitan Police of London, after which many regional police forces are modeled.

Police officers have a limited local jurisdiction, usually within the boundaries of a city or town. Their responsibilities vary and differ from political context to another. Within their jurisdiction, the typical duties of the police is keeping the peace, public safety, citing and arresting people, and the investigation of crimes. They also perform a variety of public services including safety education and security within city limits. Officers are expected to respond to a variety of situations that may arise while they are on duty. There are rules and guidelines, which dictate how an officer should behave within the community. Police officers in nearly all countries retain their lawful powers, even off duty.

The process of becoming a sheriff is very similar to the training of a policeman. In both cases, the candidates must take a written examination to qualify. They undergo a physical examination and a background check. If the candidate passes, they are interviewed, and then sent to the training academy. At the academy, the cadet learns and participates in the academic program designed to prepare them for active duty.

Comparison between Sheriff and Cop:

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