Non-renewable resource

A non-renewable resource (as opposed to a renewable resource) is a resource that can't be obtained in indefinite quantites in survival without exploring more terrain, assuming glitches or commands aren't used. While running out of a resource isn't likely to be a factor in normal gameplay due to massive size of an Minecraft map, in principle there is only a finite quantity of these resources available in each Minecraft world.

Most non-renewable resources aren't renewable because they can be only obtained through crafting recipes which consume non-renewable items, others can only be obtained by finding them as naturally generated blocks, in structure loot chests or as a drop from certain enemies which don't respawn; elder guardians, illagers and shulkers, which only spawn as a part of structure generation, and the wither, which can only be spawned by using non-renewable soul sand.

Many normally renewable resources become non-renewable, and in some cases unobtainable if playing on peaceful difficulty, as monsters will not spawn.

The degree of impact the non-renewability of a resource has on normal gameplay generally depends on how limited the resource in question is, but on custom maps these relationships may be changed, for example on many Skyblock-style maps dirt is extremely valuable, as only a small amount is available and it has many important uses.

Common
While technically not renewable, these resources or their non-renewable raw materials are so common in the default world generation that they are unlikely to be used up in even in relatively small areas of the map, assuming they contain the appropriate biomes. Their non-renewability may be more important in custom maps.

Less common
While these resources are still common, players may be pushed to explore further to find more, especially if multiple players are collecting them. In many cases they aren't truly exhausted, but finding and collecting the remaining material is far harder than simply exploring for more. For example nether quartz generates throughout netherrack, but many players only harvest the veins visible on cavern surfaces.

Rare
These resources are limited enough to force players wander far and wide to find them in any significant quantity, especially on servers.

Not obtainable in Survival
These resources are not obtainable as items in Survival Minecraft, however they can be encountered and some even created or manipulated in survival.

Not encountered in Survival
These resources cannot be accessed without using creative mode or commands.