-Sayed Mahbub Hasan Amiri Introduction: Public Relations (PR) is often confused with advertising. It is, however, a distinct branch of communication and involves informing and educating the public about the activities or philosophy of an organization. Some companies have their own PR departments, while others appoint consultants or agencies specializing in the job. The keyword is communicating the company’s point of view to various target groups, in an effective manner so that a favorable impression is formed. PR is, thus, a powerful management function and a serious business activity. It does not mean merely building relations with different groups. Definition: Ivy Lee and Edward Louis Bernays established the first definition of public relations in the early 1900s as - "a management function, which tabulates public attitudes, defines the policies, procedures, and interests of an organization... followed by executing a program of action to earn public understanding and acceptance." In August 1978, the World Assembly of Public Relations Associations defined the field as -"the art and social science of analyzing trends, predicting their consequences, counseling organizational leaders, and implementing planned programs of action, which will serve both the organization and the public interest." The Public Relations Society of America (PRSA) defined public relations in 1982 as: "Public relations helps an organization and its publics adapt mutually to each other." In 2011 and 2012, the PRSA developed a crowd-sourced definition: "Public relations is a strategic communication process that builds mutually beneficial relationships between organizations and their publics." Public relations can also be defined simply as the practice of managing communication between an organization and its publics. The European view of public relations notes that besides a relational form of interactivity there is also a reflective paradigm that is concerned with publics and the public sphere; not only with relational, which can in principle be private, but also with public consequences of organizational behavior. Role of the Librarian : The primary function of a reference librarian of any library is answering user query. Reference librarians have inherent obligations to provide information service to support the educational, recreational, personal and economic endeavours of their user communities as appropriate to the missions of the library. The reference librarian establishes a mutual relationship with the users and always appears welcoming in order for the user to find it easy to approach the reference desk. He or she serves people who work independently to find information, but who need a little help from time to time. The reference librarian as part of his public relations activities teaches users regularly how to make effective use of the library and the need to obey library rules and regulations. The current awareness services rendered by the reference librarian is of great importance to the users as it helps in keeping up to date with the current literature in a particular subject. The reference librarian also performs a guiding role by assisting the users to rephrase his or her question(s) in order for such question to be meaningful and then directing the user to appropriate information resources. Assisting the users to rephrase his or her question is one of the most important works a reference librarian does, because this enables the reference librarian to match the patron’s question to a relevant and useful source. The reference librarian provides reading guidance to individual. Readers’ advisory involves recommending to users what they might read. The reference librarian also play the role of building collection for the library and the user by selecting, evaluating and recommending relevant materials not only for the reference collection but the library collection as a whole. This is in order to ensure that there are relevant and adequate resources in the library to meet users’ information needs. Conclusion: The importance of PR is growing by the day. Both government departments and the private sector have realized that advertising must be supplemented with an effective PR. This helps in two aspects: first in keeping close to the customer to satisfy needs and anticipate changes in customer demand, and second, to create a favorable impression among the people which advertising may sometimes not do. A happy customer will most likely make repeat purchases, so an effective PR makes a good business sense too. It is a means to win customer loyalty.