It's possible to think of the internet as the world's biggest library - but instead of books, its shelves contain billions of individual web pages.
Imagine being in such a vast library. It would take forever to find what you were looking for!
Every library has an index to help you track down the book you want. The internet has something similar in the form of 'search engines'.
Find websites fast
. Search engines are special websites that have indexed billions of pages - and make it easy for you to find a website or page in an instant. Popular search engines include Google, Yahoo!, Bing and Ask.
To get to a search engine you just need to go to your browser's address bar and type in the address of the search engine website, or you can use the search box that's usually found in the top right-hand corner of a browser.
Each search engine works in a similar way. If you go to a search engine's homepage, you'll find a single box. You simply type whatever you want to search for into that box.
Using key words
If you wanted to search for days out in London, you could type London days out into the search box and then either press 'Enter', or click on 'Search' or the search symbol (which can be a magnifying glass).
You'll get a list of the most popular web pages that contain the words you typed in.
You could search again using more key words. So instead of just London days out, you could add the word kids. Now your search results should give you pages relating to days out in London that kids might enjoy.
You can keep on adding more key words to narrow down your search results further.
Minus key and quote marks
If you wanted to exclude certain pages from your search, you could use the minus operator (sign).
Therefore, if you only wanted to find indoor attractions, you could add -outdoor to your entry in the search box. This would filter out any results that mention 'outdoor' on their web page.
Another useful trick is to add quote marks around more than one word so they are searched for as one term, rather than each word separately.
For example, searching for tourist attractions would mean that the search engine looks for any page that contains the word 'tourist' and contains the word 'attractions' - which could be a site for people who are attracted to tourists!
By putting quote marks around the words - to make it "tourist attractions" - the search will only look for pages with these words next to each other, as one term.
You can search for all sorts of information using a search engine - holidays, videos, news articles, music, pictures, maps… The possibilities are endless!
But it's important to remember that search engines are a bit like robots - they don't check the truthfulness or the reliability of the information they find.
Also, it's possible for companies to pay the owners of search engines for their pages to appear at the top of searches or as adverts called 'sponsored links' (these typically appear at the top and down the right-hand side of the search results).
So, just be aware that not all search results are based on the popularity of a site.