The document discusses transmitting and receiving data between information systems. It describes serial and parallel transmission methods and how compatible communication systems are required using settings like baud rate and parity. Different transmission types are explained, including asynchronous, synchronous, simplex, half duplex and full duplex. The role of modems in converting digital to analog signals for telephone line transmission is also summarized.

1. Lyell & Lee Transmitting & Recieving

8. Role of Modem

12. Communication software It uses protocols to establish a connection. A protocol is a set of rules that governs the transfer of data between hardware. It defines how the information is transmitted and how errors are detected. The 2 pieces of hardware must use the same protocols, otherwise the data transfer may be unsuccessful. Some popular protocols for networks are Ethernet and token ring. This image shows how important communication software is because it allows and manages the transfer of data, files and commands between different types of hardware.