HOMONYMY

Homonymy

Homonyms are different lexemes with the same form (written, spoken or both). For example, bank is both an elevated area of ground and a place or business where money is kept. You may think these are the same words, but this is not so, since the meaning is an essential feature of a word. In some cases, the same form (as with paper) has the same origin but this will not always be the case. The etymology of a lexeme will tell us where it comes from and how it acquired a given meaning.
Identity of form may apply to speech or writing only. David Crystal calls these forms “half” identical. They are:

• Homophones - where the pronunciation is the same (or close, allowing for such phonological variation as comes from accent) but standard spelling differs, as in flew (from fly), flu (“influenza”) and flue (of a chimney).
• Homographs - where the standard spelling is the same, but the pronunciation differs, as in wind (air movement or bend) or refuse (“rubbish” or “disallow”, stress falls on first and second syllable, respectively). 
•  Heteronymy. Heteronyms are homonyms that share the same spelling but have  different pronunciations. That is, they are homographs which are not homophones. Such words include desert (to abandon) and desert (arid region)
•  Capitonymy. Capitonyms are homonyms that share the same spelling but have different meanings when capitalized (and may or may not have different pronunciations). Such words include polish (to make shiny) and Polish (from Poland).
  

       A DIDACTIC VIDEO ABOUT HOMOPHONE

http://www.teachit.co.uk/armoore/lang/semantics.htm#15
Notes from Topic: Semantics, Linguistics Signature, Ms Jimenez, Yolanda, Universidad Camilo Jose Cela
http://en.wikipedia.org/wiki/Homonym
http://www.youtube.com/watch?v=HS8lsaAIL-0&feature=related