Public health sector works and administers several programs to prevent diseases and promote health in a community. In short, public health department works for the overall well being of the community. The main aim of the public health unit is to keep surveillance on the unhygienic activities that contribute to ill health. The public health division plays an important part in educating the society to follow the healthy measures advocated to keep away from diseases. Immunization program is a typical example of activity undertaken by the public health sector. The division also prevents the further spreading of infectious diseases during their onset. Public health agency in a country is usually a governmental body. In addition to that, several international organizations actively take part in the major public health issues.