Dedupe type in civicrm

In civicrm, there is Dedupe functionality which check the duplicate contacts & merge it .
It check contacts for contact type ( like Individual, Household, Organization )  .
To open dedupe click on Contact .
It gives condition on which civicrm checks duplicate contact .

If we add the rule just go to edit rule or create new dedupe .

Default Dedupe Rule Settings

Fuzzy Rules for

• Individual => First Name AND Last Name AND Email
• Organization => Organization Name OR Email
• Household => Household Name OR Email

Strict Rules for

• Individual => Email
• Organization => Organization Name OR Email
• Household => Household Name OR Email