Dear Kathir

with regard to ur clarification ,see here we are doing two things

1.while ur are infroming to the candidate about your company details and other important stuff you are marketing your company and building confidence in him
2.The other point is you are making the candidate to become tension free and giving time to relax and perform well in the interview

and if our company is small and if we have more competetion in the market and not known to all and new, then we need to tell candidate all the details to market our company ,how we are better in products ,services ,etc .our website may not give all the details or have too much complex things on it intended to serve different people visting it

regards
Satya vegi