Best Answer:  both will malfunction if attacked by virus. 
both has a limited memory 
both can explore various sites. 
both has their own briefcases. 
both has their own calculators 
both can import and export 
both can act as a messenger 
both can write a mail 
both can paste 
both can save 
both has their own favorites 
both has their own tools 
both can play games 
When tired and slow both has to refreshed 
both carry a address book,note pad and calender 
sometime both require a help 
both could be repaired and cured by only by qualified technicians. 
Both function and look better with Add-ons 
both ask questions and answer questions. 
By over usage both get heated up. 
Both have network places 
Both have choise to run 
Both can play music 
The list is endless therfore to put it in netshell.... 
both are like husband and wife they can not function alone 
with 100% perfection and happiness without each other.