Renewable resources are items consumed that replace themselves at a constant rate, such as oxygen, water, food (both plant and animal), and forestry. One of the benefits of renewable resources is that what is taken can be replaced. So, you cut down a tree, another tree will grow or can be planted to replace the one you cut down. However, one thing to consider is that the resource is renewed at its own rate. Looking back at the tree example, you can replace the tree you cut down; however, it will take 10+ years for the tree to regrow.
Nonrenewable resources are items consumed that do not replace themselves, such as oil, coal, and certain earth minerals. Once these are consumed, they are gone forever because the earth has already produced the amount of these items it will produce.