GET YOUR HEAD AROUND KEYWORDS

When you are writing anything for your website, you automatically include keywords in your text, after all, these are the words which tell people what you are on about, whether your are selling something or offering information only.
The search engine “bots” pick up on the keywords and keep immense databases of them.
“Keyword phrases” need to be mentioned here too, you might be selling screwdrivers ( Keyword  “screwdrivers” ), but more specifically “left-handed screwdrivers”, and so if a person searching for left handed screwdrivers on the web was to enter that search term into the search engine, pages with the keyword phrase in them would appear in a ranked order of relevance and site importance.
This rank depends entirely on the search engine algorithm, and the object of the copywriter is to work with that algorithm to achieve a good search engine ranking.