Social protection is a concept widely used in many disciplines and from different perspectives. Those are some of the main reasons why it still has no concrete and overall definition. The same situation exists related to the other concepts closely connected to social protection. Those are usually used for describing the social protection system in one or another country. But still, the concepts like social welfare, social policy, and social insurance are, also need to be defined and described in the terms of the main links with “social protection” concept. The article is aimed to analyzing the concepts that are widely used in social protection sphere, but which in many cases are applied in different situations and with different meanings. It is also directed towards describing the main links between the social protection and closely related to it concepts, like social policy, social welfare, social insurance and social services are. The article is based on theoretical overview of main approaches and theories created for those concepts’ definition.