A highly reliable display apparatus, a highly reliable communication system, and a highly reliable communication method capable of performing delivery of high capacity information surely are provided. A display apparatus and an input and output terminal respectively include a light-receiving-emitting section capable of displaying moving pictures and receiving light. The input and output terminal sequentially displays each symbol composing a two-dimensional dynamic code on the light-receiving-emitting section. The display apparatus reads each symbol by the light-receiving-emitting section, acquires symbol-transmission-receiving-status information based on the read symbol, determines display conditions based on the symbol-transmission-receiving-status information, and then displays each symbol of the two-dimensional dynamic code based on the display conditions. By displaying in the aspect, in which the light-receiving-emitting section of the input and output terminal, the receiver can surely reads, contents data can be surely transmitted and received between the display apparatus and the input and output terminal.