Both databases and search engines use the 3 Boolean operators and, or, not, butthey use them differently. You must learn them.
Here is how you use the 3 operators in Google.
AND (click for example) - All the search terms must appear in the results entries
Google uses the implicit "and" because it is assumes you want all the words in your query.
You do not need to write the operator.
["climate change" canada]
OR (click for example) - Either one of the terms on either side of the operator will be searched
In Google you must capitalize OR. If you don't it will be seen as a dead word.
["global warming" OR "climate change"]
NOT (click for example) - Excludes a term you don't want in your results
Use the minus sign attached to the word to be excluded from your results.