What is Non-renewable Resource?

Legal Definition
A non-renewable resource (also called a finite resource) is a resource that does not renew itself at a sufficient rate for sustainable economic extraction in meaningful human time-frames. An example is carbon-based, organically-derived fuel. The original organic material, with the aid of heat and pressure, becomes a fuel such as oil or gas. Earth minerals and metal ores, fossil fuels (coal, petroleum, natural gas) and groundwater in certain aquifers are all considered non-renewable resources, though individual elements are almost always conserved.

In contrast, resources such as timber (when harvested sustainably) and wind (used to power energy conversion systems) are considered renewable resources, largely because their localized replenishment can occur within time frames meaningful to humans.
-- Wikipedia
Legal Definition
Natural resources such as gas, coal, etc that can be consumed only once and hence are irreplaceable. Currently, most of the energy resources that we use are non-renewable. The renewable resources are in the initial stages of development.