What is SEO ( search engine optimization)?
When you want to search some term or product you search in Yahoo, MSN, Google.
In result of your search they return the addresses of websites which have material matching your search. There are millions of results for each of your searches.
Suppose you type in yahoo / msn for
share accounting software you get 82,000,000 answers
dairy accounting software you get 4,000,000 answers
I am proud to see that in above searches my website www.shwetasoftware.com is listed as 1st or in first 3/4 entries.