In today, The online visitor almost depend on Search Engine like Google, MSN, Yahoo and many more. It is said that 70 to 80 % traffic coming from Search engine mentioned above. 

So To get a easy traffic, the best  way is, top position of website in search engine. 

SEO make our site Search engine Friendly so search engine can read our site properly and put it towards the people who really need it, SEO is easy to learn. Read some Article From Net is Good way to understand SEO or Hire some SEO Service provider company.