relevance of language teaching and linguistics

hi dear sirs,
what is the relevance of language teaching and linguistis?
would you explain it to me based on H.G widdowson's view.i have some problems to understand it clearly.
Yours sincerely
M. Barin M.A student
5. 11.2004

[Casiopea]

The best sources online is Interpreting the Discourse of H.G. Widdowson Click here, but be warned: it's pretty heavy stuff.