Parallel Adder Vs Serial Adder

Parallel Adder	Serial Adder
It is a combinational circuit which adds all the bits at the same time.	It is a sequential circuit which adds bits one by one.
Clock pulse is not required.	Clock pulse is required.
The output is in parallel form, i.e. all the bits are added at the same time.	The output is in serial form, i.e. bits are added one by one at time.
It uses registers with parallel load capacity.	It uses shift registers.
Number of full adder circuits required are equal to number of bits to be added.	It requires one full adder circuit.
It is simple in construction and number of components needed are less.	It is complex in construction and number of components needed are more.
Time required for addition does not depend on number of bits.	Time required for addition depends on number of bits.
It is less costly.	It is costlier.
It is faster.	It is slower.
It covers less space.	It covers larger space.