Anyone actually know the real difference for gardening: yams vs sweet potatoes?

[abodelook]

I have a backyard vegetable garden that I am just starting and I continue to see them used interchangeably at the nearby nursery. When it comes to the growth cycle for yams vs sweet potatoes, is one harder to manage than the other? I was reading a guide on abodelook on soil aeration of root vegetables and they recommended that special raised planters are used to avoid rot. Still, who has been growing both? My concern is that I would like to know that I have my gardening equipment and set up right before I invest my entire garden bed on the same.