What are variants?
When you have one product but with differences you have variants. For example, if you have 100 "Model X" mobile phones available in 10 different colors you have 10 variants of that particular mobile phone.
What are parent records?
Parent records are the main product records.
Let's say that you have "Model X" mobile phones that were originally manufactured in the color black. You later added other colors to your inventory as they became available. You will likely set the black "Model X" mobile phone as the parent record and the other colors as variants.
During the import process, you have the option of setting up product variants. During this step, you'll identify which column or attribute in your import identifies the relationship between your master or parent products and your variants.