Disclosed are a display device, etc. which display information in a display format that provides high visibility. The display device 201 comprises a display unit 202 which displays first nodes, each representing a different communication entity with communication capabilities, or second nodes, each representing a different group of a plurality of communication entities, around a first region, and which shows communications being carried out between first and second nodes, between a plurality of first nodes, or between a plurality of second nodes, in a display format in which the connections between these communicating nodes are indicated within the first region.