This paper shows an overview of the different concepts and techniques that are been used in social network analysis; also it shows new uses of SNA and different challenges that it is facing.In a first moment, it illustrates the way of representing the social networks through graphs of matrices, highlighting the importance of nodes in the graphical method and the wider application of the second method, due to the mathematical thechniques used there. The importance of nodes is deepened, the different techniques for analysis; and they are defined, their influence is established and the disadvantage of their use is mentioned. Similarly, a comparison of the techniques used to analyze the strength of ties that unite these nodes, defined as the combination of a series of characteristics of these relationships, is presented. In addition, an analysis of the new uses of SNA and the challenges that it faces, oriented to the verification of the accuracy of the information, is made.As a conclusión, it can be observed that the Social Network Analysis, SNA, can be applied in many fields and that is a need the research and development of new systems, techniques and analytical tools in this áre. In this process it is important to take into account the basic role played by engineers, mathematicians and sociologists in predicting the behavior of different social networks and in the design and generation of these new techniques.