Google's Advanced Search web form gives several additional fields which may be used to qualify searches by such criteria as date of first retrieval.
All advanced queries transform to regular queries, usually with additional qualified terms.
Search engine optimization encompasses both "on page" factors (like body copy, title elements, H1 heading elements and image alt attribute values) and Off Page Optimization factors (like anchor text and Page Rank).
The general idea is to affect Google's relevance algorithm by incorporating the keywords being targeted in various places "on page", in particular the title element and the body copy (note: the higher up in the page, presumably the better its keyword prominence and thus the ranking).
Google not only indexes and caches web pages but also takes "snapshots" of other file types, which include PDF, Word documents, Excel spreadsheets, Flash SWF, plain text files, and so on.
Google has been criticized for placing long-term cookies on users' machines to store these preferences, a tactic which also enables them to track a user's search terms and retain the data for more than a year.
For any query, up to the first 1000 results can be shown with a maximum of 100 displayed per page.
The ability to specify the number of results is available only if "Instant Search" is not enabled.
That swells to 79 or so the number found circling the giant planet since Galileo spotted the first of them with a homemade telescope more than 400 years ago.
The main purpose of Google Search is to hunt for text in webpages, as opposed to other data, such as with Google Image Search.