An unlimited Google search checks all available domains for your search terms, which may return results that are not specific enough for your needs. One way to make your search more relevant is to limit it to a specific domain.
How do I search on Google – limit the results to a specific domain extension?
Many website addresses end in .com, which is the most common top-level domain (TDL). However, it is not the only one. There are other top-level domains that use different suffixes. Some of the most common ones are:
To search for a specific top-level domain, precede it with site: followed by the TLD suffix with no space between them. Then add a space and type the term for your search.
For example, suppose you are looking for information about textbooks, but you do not want to buy a textbook. A web search would show you primarily websites that sell textbooks. To instead get non-commercial search results about educational textbooks, restrict your search to the .edu top-level domain by typing this into the search field:
