The best way to find out how web search tools work is to try searching!
Some search engines offer the opportunity to search particular types of resource – look on the Google home page and experiment with looking for a search term under ‘images’ only and then in ‘scholar’ and see what results you get. Make a note of the different categories you can search under – this may be useful to you later in your studies.
Some search words you may wish to use may have different meanings and uses in different contexts. This may cause confusion when searching text resources and make it more difficult to get the results you want. Try searching for ‘birds’ on Google and see what happens. Google recognises that the word is used in many different contexts and if you scroll down the page you will see that you are offered a range of possible related searches to refine your results. If this grouping doesn't happen and you are still getting too many unsuitable links then you need to think carefully about exactly which words you use for your search terms and make use of ‘advanced’ search to limit the number of hits further.