Data and Signals

In computer networking, data is the essential information we want to transmit, which can include text, audio, video, or files. However, data cannot travel directly through communication mediums like wires or air. Instead, it must first be converted into a signal that can move through these mediums.

A signal serves as the physical representation of data, allowing it to travel from one device to another. Depending on the medium and the type of communication, signals can be classified as analog, which are smooth and continuous, or digital, which consist of discrete binary pulses.

The effectiveness of data transmission relies heavily on how well the signal is matched to the transmission medium. For example, digital signals are well-suited for Ethernet cables, while light signals work best with fiber optics.

Note: Both data and signals can be either analog or digitals.

Data (in Networking)

Data is the collection of raw facts, figures, or information that is intended to be communicated, stored, or processed by devices in a network.

• It can be text, audio, video, images, or binary information.
• Data is what we want to transmit from one device to another.

Data cannot be transmitted directly over a medium without being converted into a signal.

For Example:

• Digital data to Digital signal: For short-distance transmission (like inside a computer or over Ethernet cables).
• Digital data to Analog signal: For long-distance transmission (like over telephone lines or radio waves), using modulation.

Signal (in Networking)

A signal is the electrical, optical, or electromagnetic (radio, microwave) representation of data that is used to transmit the data across a communication medium.

• Signals are the physical form of data used for transmission over a medium like copper wires, fiber optics, or air.
• Signals can be analog signals (continuous waveforms) or digital signals (discrete pulses (representing 0s and 1s).
• Signals and medium must be compatible.
  • Digital signals transmitted over twisted-pair Ethernet cables work efficiently because the cable supports discrete voltage levels.
  • Light signals cannot be sent through copper wires, as copper does not support optical transmission.

Data vs Signal

Data, Signal, Medium, and Application Table

Important:

• Analog signals are used for smooth, continuous data such as traditional voice or music.
• Digital signals are better suited for binary data, like computer files and video.
• The choice of medium depends on the type of signal and application requirements, including speed, distance, and noise.