The world is a big place. With over 4.6 billion people and counting, there's a strong possibility you could be related to certain people and not even know it. If you want to find out if you're related to someone, there are a few ways you can go about it.
If you think you're related to someone, the simplest way is to ask them directly. Ask them what town they came from and the names of some of their close relatives.
If the names they provide don't ring a bell, ask an elder family member. The elderly tend to know more of the family's history and can help you create a family tree that could link to someone who is related to the person you are questioning.
While the Internet isn't always the best place to share personal information, genealogy websites can help trace family roots through the use of databases and past census reports. Through a website, you can create an elaborate family tree that could show connections to many family members about whom you never knew.
If you find a genealogy match that you think proves your relationship to someone, verify that information by contacting living family members of that link, even if they are overseas, to try to trace the family line and see where you belong.
DNA testing is the most expensive option for proving if you're related to someone. It requires a cheek swab to be collected from both parties to be tested for familial relations. This test is similar to paternity tests that are used to prove who is the parent of a child, or the immigration test to prove relation to family members already in the country. The DNA sample is the most direct way to prove bloodline.