Engineer 

An engineer is a professional practitioner of engineering, concerned with applying scientific knowledge, mathematics and ingenuityto develop solutions for technical, social and economic problems. Engineers design materials, structures and systems while considering the limitations imposed by practicality, safety and cost. The word engineer is derived from the Latin roots ingeniare("to contrive, devise") and ingenium ("cleverness").

Engineers are grounded in applied sciences, and their work in research and development is distinct from the basic research focus ofscientists. The work of engineers forms the link between scientific discoveries and their subsequent applications to human needs and quality of life.

Dentist

A dentist, also known as a 'dental surgeon', is a health care practitioner that specializes in the diagnosis, prevention, and treatment of diseases and conditions of the oral cavity. The dentist's supporting team aides in providing oral health services. The dental team includes dental assistants, dental hygienists, dental technicians, and in some states, dental therapists.

Architect

An architect is a person trained in the planning, design and oversight/supervision of the construction of buildings. To practice architecture means to offer or render services in connection with the design and construction of a building, or group of buildings and the space within the site surrounding the buildings, that have as their principal purpose human occupancy or use. Etymologically,architect derives from the Latin architectus, itself derived from the Greek arkhitekton (arkhi-, chief + tekton, builder), i.e. chief builder.

Professionally, an architect's decisions affect public safety, and thus an architect must undergo specialized training consisting of advanced education and a practicum (or internship) for practical experience to earn a license to practice architecture. The practical, technical, and academic requirements for becoming an architect vary by jurisdiction (see below).

Doctor

A doctor is a professional who practices medicine and trying to maintain and restore human health through the study, diagnosis and treatment of the patient's illness or injury. In the Spanish language, colloquially, is also called doctor these professionals, but have not obtained the doctoral degree. The doctor is a highly qualified professional in healthcare, it is usually able to give accurate and rapid responses to health problems, usually by decisions made under conditions of great uncertainty, and that requires continuous training throughout their lives labor.

Police Officer 

A police officer is a warranted employee of a police force. In the United States, "officer" is the formal name of the lowest police rank. In many other countries, "officer" is a generic term not specifying a particular rank, and the lowest rank is often "constable". In many other countries there is no such title as "police officer", as the use of the rank "officer" is legally reserved for military personnel only and thus not applicable. Police officers are generally charged with the apprehension of criminals and the prevention and detection of crime, and the maintenance of public order. Police officers may be sworn to an oath, and have the power to arrest people and detain them for a limited time, along with other duties and powers.

Some police officers may also be 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.