Search engines are one of the two main types of websites used for finding sites on the web - Directories (such as the Open Directory Project) being the other. Search engines work by crawling the web1 and indexing the contents into their databases or by asking people to come forward and submit their site to the search engine's database.
There are many different types of search engines that have many different ways of letting you search their databases, either for websites or pictures or even audio files:
Favoured by Altavista, this type of search requires you to put + or - signs after search terms in order to narrow the search and find exactly what you're looking for. The minus sign allows you to omit a term so if that term appears on a page that page will not be shown or not be given a high priority2. The plus sign allows you to force the search engine to give priority to sites containing that word or omit sites that don't contain it. Some search engines ask you to put in words in capital letters instead of + and - signs (eg 'AND' and 'NOT').
If you're searching for information about the band Nirvana, you may find that you get a result which contains nothing but pages about Buddhism. You can refine your search by using either '+' or '-'. If you enter 'Nirvana -Buddhism' into the search field the search engine will eliminate all pages which contain the word 'Buddhism'. On the other hand you can enter 'Nirvana +Cobain', the results will only contain pages which contain the words 'Nirvana' and 'Cobain'3.
Search by Field
This allows the user to specify where the search terms should be on the page to get high priority or be included in the results. This could mean that the term must be in the title of the page or as part of the URL4 address. This option is usually available in the 'advanced search' page of the site.
Exact Quotation Searches
Using double quote marks in some search engines, such as Yahoo! will allow the user to make sure the terms are in the exact right order and are together. This can be useful if a search provides a lot of irrelevant results which contain the terms but not in the relevant order.
Quotation marks allow you to search for exact phrases. If, for instance, you want to know which film the phrase 'In space no-one can hear you scream' was the tagline for, you could simply type in the words, but what you'll get is every single page out there with any one of those words on it. If you put the entire phrase in quotes however - "In space no-one can hear you scream", the engine will only search for pages which contain that exact phrase. This is very handy when using the search engines on sites such as Amazon.com, eBay, and The Internet Movie Database to find the title of a book, album, or film.
Some sites, such as BBC use filters to narrow their searches. The most common types of filters get rid of 'adult' sites, to stop harm to children, but some also filter their searches so the results are more relevant to the country their server is based in5.
In an attempt to make your search easier, Kartoo have come up with the idea of displaying your search results as a visual mind map of connections between different sites. Whilst it can be a little difficult to understand, some have found it a very logical way of finding what they are looking for.
Natural Language Searching
This allows the user to type in a search query in the form of an English question, eg 'What is the best Internet site on the Internet?' would come up with the answer 'h2g2'6. This is useful when you are looking for specific information and don't want to spend too long finding it. Ask Jeeves was the first site to use this feature.
Following on from the Ask Jeeves idea of natural language searching, Google did away with the need to even ask a question. All the user has to do is type in the search terms, click enter and the engine will return all websites that have the search terms in them. Note: Google will only return pages which include all the words you supply, unless you go to its 'advanced search' feature and change this option. Google will then assign an importance to each result based on how popular the page is on the web. This is judged mainly by the number of other pages that link to it and who links to it7. The results are then displayed with the most important first. This usually pushes personal websites down to the bottom of the list and 'official' sites to the top. The creators of the site claim that this is the feature that sets Google apart from its competitors. GoogleBlog will keep you abreast of new developments/features within the site if you ever get lost.
Be patient! Search engines are computers deep down and it may take a while before you find the page you're looking for, but in the infinite reaches of the Internet you will find what you're looking for.
Staying Ahead of the Game
Search Engine Watch offers you the chance to keep an eye on the developments in the ever-expanding8 search engine world. Also, there are some sites, called meta search engines, such as MetaCrawler, which let you search many search engines at a time, removing any duplicates.