Every one of us know how to search in google .But there are little tricks which makes your searching much more efficient than the normal users.Whenever we search for more than one keyword at a time, a search engine has a default method of how to handle that Keyword.Will the engine search for both keywords or for either keyword?
The answer is called a Boolean default. By default google do BOOLEAN AND ( i,e both words) or BOOLEAN OR ( either ) .you can usually give it a special command to instruct it to search for either keyword (OR).
Google OR Microsoft
For the above search query it finds results containing information on Google or Microsoft. ( Give it a try ).
excluding OR will find pages containing both Google and Microsoft.

Do you know
Green cyber surfers beware – just two searches in Google can use up as much electricity as making a cup of tea.
One search engine request burns up about 7g of carbon dioxide, latest calculations found – compared with 15g for boiling a kettle.
Looking at a single page on the internet generates about 0.02g of CO2 per second, US physicist Alex Wissner-Gross said.
If you want to have definitely one term and one of two or more other terms, you group them with parentheses, like this:
OrACLE (Java OR “Web Services”)
This query searches for the word “Java” or phrase “Web Services” along with the word “XML.” A stand-in for OR borrowed from the computer programming realm is the | (pipe) character, as in:
XML (Java | “Web Services”)
And If you want to specify that a search item must not appear in your results, use a – (minus sign or dash).
salsa -dance
this finds pages containing the word salsa but NOT the word dance.
In the next part , we will see how to restrict google seach using commands like “filtype:” , “inurl” , “link:” etc.