In this paper we consider immersive visual media that are currently researched within scientific community. These include the well-established technologies, like 360-degree panoramas, as well as those being intensively developed, like free viewpoint video and point-cloud based systems. By the use of characteristic examples, we define the features of the immersive visual media that distinguish them from the classical 2D video. Also, we present the representation technologies that are currently considered by the scientific community, especially in the context of standardization of the immersive visual media in the MPEG-I project recently launched by ISO/IEC.