What are composite signals why you needed?

In case of TV broad casting, the Video Signal is not transmitted alone, but it accompanied by a number of other signals or pulses, which help the exact reproduction of the picture at the receiving end. These pulses include Blanking Pulses, Synchronizing pulses and Equalizing pulses. A combination of Picture signal and other Controlling signal or pulses is called Composite Signal. Thus Composite Video Signal may consist of Following Parts.

1. Picture information (Data)
2. Blanking Pulses (Delay Pulses)
3. Vertical and Horizontal Synchronizing Pulses (controlling Pulses)

Generally,

A Combination of Data and Other Controlling Signal is Called Composite Signal .