Refurbished items are typically those that have been used before (for a long time, based on the good condition), and then fixed up to work like new. Renewed items are typically new but not in their original packaging.
Refurbished is usually at a lower price because you’re still buying something that has had some use. However, with refurbishing companies determine which pieces should be replaced and such, so it could potentially cost more for a refurbished item than for cutting corners with your own DIY project! When you go with the renewed option, you should know what you’re getting into ahead of time – it might not necessarily feel like it was brought right from the store.