The bandwidth refers to the difference between the highest and the lowest frequencies of a transmission channel.
You can also say that bandwidth refers to the width of allocated band of frequencies to a channel.
Bandwidth is directly proportional to the amount of data transmitted or received per unit time.
You can also say that bandwidth is proportional to the complexity of the data for a given level of system performance. For example, it takes more bandwidth to download a photograph in one second that it takes to download a page of text in one second.
Large sound files, computer programs, and animated videos requires still more bandwidth for acceptable system performance.
Note - High bandwidth channels are called as broadband channels and low bandwidth channels are called as narrowband channels.
In digital systems, bandwidth is the data speed in bps (stands for bits per second). Therefore, a modem that works at a speed of 57600 bps has twice the bandwidth of a mode that works at a speed of 28800 bps.
In analog systems, bandwidth is defined in terms of the difference between the highest-frequency signal component and the lowest-frequency signal component. Frequency is measured in cycles per second i.e., hertz. A typical voice signal has a bandwidth of approximately 3 KHz (3 kilohertz) and an analog TV (television) broadcast video signal has a bandwidth of 6 MHz (6 megahertz).
Here the table given below describes different units to measure bandwidth:
|A||kilohertz||kHz||a thousand cycles per second|
|A||megahertz||MHz||a thousand kHz|
|A||gigahertz||GHz||a thousand MHz|
|A||terahertz||THz||a thousand GHz|