You can define a parent product to have many child products. This is used when you have a main product but with many variations by size, color or other attributes. A parent product itself is a non-inventory product. It is used to link all the children products together.
To set up a parent product, first create a non-inventory product and save. Then click on the Set As a parent button to make this into a parent product.
If the child product is already created, go find the product and then edit the product. Click on the button Assign parent product. Find the parent product by entering its name. Click save and the child product is now associated with the parent product.
Now when you are viewing the parent product, you will see all its child product listed.
If the child product is not present, create it as an inventoried product first and then assign a parent to it. If you no longer wants a child product to be associated with a parent you can delete this relationship while viewing the parent under product associations
A parent product and child product still behave like any other products, with the only exception you cannot put a parent product in a sales order, you must choose a child product instead.