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What are Signals in Computer?Forms of Signals

August 30, 2022

The signal is an electromagnetic or light wave that represents data. Signals in computers are sent through a communication medium in order to conduct data transmission. Signals are created by sending an electric current through the medium.

The receiving device then goes through the same process, which turns the current into sound, image, or text. Data signals can be man-made or natural. Signals can also be big and small. Big signals are referred to as ‘broadband’ signals since they have a large bandwidth.

Forms of signals

The signals are in two forms

  • Digital Signals
  • Analog Signals

Digital Signals

A digital signal is a series of ones and zeros that represent information. A digital signal can be represented by a voltage level or current flow. In electronics, a digital signal is often represented by a voltage level. When a voltage level changes, it represents a 1 or 0.

There are two types of digital signals: positive and negative. Positive digital signals have a higher voltage than negative digital signals.

All data communication between computers occurs in digital form. This is because computers can only understand and work with digital signals. The following figure represents a high voltage signal as a 1 and a low voltage signal as a 0.

Analog Signals

An analog signal is an electrical signal that takes the form of a wave. This wave is known as a carrier wave. The most common medium used for transmitting analog data is a telephone line. However, light, sound, radio waves, and microwaves are also examples of analog signals.

Characteristics of Analog Signal

Two characteristics of analog signals are as follows.


Frequency is how often a wave occurs during a specific time interval. Frequency refers to the number of times something happens per second. In audio, frequency refers to the pitch of the sound.

A higher frequency means a higher-pitched sound while a lower frequency means a lower-pitched sound. When we talk about frequency in electronics, it refers to how often a voltage changes (or current flows).


The height of a wave within a given period of time is known as amplitude. Amplitude is how much something is changing. Amplitude refers to the amount of power being sent out. If we have a sine wave, then its amplitude would be at its peak. If we had a square wave, then its amplitude is at 0.