whats the difference between "advertising"and "advertisement"

Question

Answer

Advertisement -- this is a noun, sometimes shortened to "ad".  
  (There are many advertisements on TV.)
Advertising -- this can be used as a verb or a noun (and an adjective?).  As a verb, it means to advertise.  
  (Many English teaching companies were advertising during the Olympics.)  
As a noun, it means advertisements generally.  
  (We don't plan to purchase any advertising this year.)
Like many nouns, it can also be used as an adjective -- (the advertising department of a company)
Hope that helps...

Answer

Advertising is the verb whilst advertisement is the noun. You can also say ' add'