All forms of stored messages are, by definition, non-simultaneous communication. The two primary types of conduit are wired are wireless. Wired transmissions travel over copper wire, coaxial cable, or fiber optic cable. Wireless transmissions use a particular frequency and bandwidth within the electromagnetic spectrum, or, in the case of sound waves, vibrations in the atmosphere. Many CIS use combinations of both wired and wireless, including broadcast and cable television, radio, and cordless and cellular telephones.
Content stored digitally has several advantages, the most important of which is ease of access.
The use of digital representation for the creation and presentation of messages provides a variety of modest space and time savings in content storage and transmission, and provides substantially more user control over message presentation. However, the biggest difference between analog and digital representations comes at the stage of message preservation. First, digital content, from e-mail messages to airline reservations, can be easily accessed and most of it is easily searchable. Every communication and information system has a certain number of access points, or nodes. The capacity of the system should not be confused with the ability of people to use the system.