Public Relations is an inseparable part of every successful company nowadays. The present article introduces some important aspects of Public Relations starting from the history of PR, then describing what Public Relations is and the aims it pursuits. Then it focuses on the areas where Public Relations exist and explains the link between them. There are certain tools and channels that are used in Public Relations, and each of them has its pros and cons. Here, we also talk about the differences between Public Relations, Advertising and marketing, meantime showing how the system of marketing mix works, and the role that PR plays in it. We highlight the differences that exist between advertising and Public Relations and introduce the PR campaign process in accordance with the R.A.C.A. principle.The aim of the present article is to provide a theoretical background and introduce the basics of PR.The methods that have been used in the present article are; descriptive and comparative.The obtained results of the study can be implemented in all spheres of public relations.It can be concluded that Public Relations is an inseparable part of the operation of all companies and organizations regardless of the sphere of their operation.