A sine wave when rectified it is called pulsating dc but in square wave it is different. A square wave can be with positive and negative peaks or it may be simple pulse either negative or positive. There is also another term pulse train which is a series of pulses. I want to know that do all of these are square waves.
These are all square waves yes except pulses need not be square waves. Various pulse shapes other then square waves exist such as the raised cosine pulse response.
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Raised cosine pulses are for example used in communications instead of square shaped ones to reduce intersymbol interference
Square waves are pulses which are symmetrical....
Talking interms of duty cycle....if it is 50% then it is a square wave....
so, square wave is pulse but all pulses are not square waves...
A "true" square wave is a symmetrical wave with a 50% duty cycle. But i think the square wave term can be used loosely for ones other then with a duty cycle ratio of exactly 50%.