Search Engine Optimisation - What is Search Engine Optimisation?

What is Search Engine Optimisation?
Search Engine Optimisation is the process of making websites search engine friendly. The process often involves minor modifications to, or additions of, several standard elements of a website.

If these elements are so important, why didn't they get added when my site was originally designed?
Most website designers haven't learned the importance of search engine friendly design. In almost every case, the site designers are highly skilled and creative people whose jobs are to put your ideas on the web. More often than not, the designers have not received any training in search engine optimisation and don't think about it while pursuing a cool looking design. Search engines are also constantly changing their ranking criteria. They do this to prevent gross manipulation of their search tools. Often, website designers are not fully up to date with changes at search engines.