What is the connection between DNA and family trees?

DNA and family trees complement each other. DNA can be used to prove or disprove documented family tree connections. For example, if there is another person with your surname, or a family tree owner with whom you have a Smart Match™, you can both test on MyHeritage DNA to find out if you are indeed related.

Conversely, family trees are invaluable for understanding the relationship path to DNA matches. Creating a family tree is recommended for anyone taking a DNA test, to make the most of the DNA results and to uncover the full story behind them. MyHeritage provides excellent tools for creating a family tree, and 7 billion historical records that make it fun and easy to expand it.

For further instructions, please read these articles: 

How do I create my family tree on MyHeritage?

How do I bring my family tree information from another genealogy program to MyHeritage?