>>21526630 (OP)
Oh, I know a lot about this so I'll infodump.
Every spirit starts as a base material (wheat, potato, agave, sugarcane, fruit, etc) which is mashed, fermented, distilled, diluted, and maybe aged.
For many spirits, the base material matters a lot. Tequila must be made from agave, rum must be made from sugarcane (or more practically, sugarcane byproducts like molasses), whiskeys are made from grains, brandy is made from fruit, etc. These spirits are intentionally distilled less than they could be to keep some of the properties of the base material in the spirit. Other spirits, like vodka/gin/absinthe, are distilled to the point where nearly pure ethanol (and because of weird physics, some water) is all that's left, so it doesn't really matter what their base material is. Anything that can be fermented will work. They're generally made from cheaper base materials like wheat or potato since it doesn't matter and using a more expensive material would just be a waste. Vodka is just diluted ethanol, gin is the same thing but with an extra second distillation step involving adding botanicals so it tastes like juniper berries and pine needles, and absinthe is like gin but with wormwood and anise instead of juniper and pine.
Some spirits are then aged in wooden barrels to take on the flavors of the wood. Traditionally, light spirits are un-aged and dark ones are aged, but there are plenty of exceptions to that. Silver tequila is unaged, while aged tequila spends a few years in oak barrels. White rum is un-aged, while dark rum is aged. Vodka and gin aren't usually aged, and whiskeys are almost always aged.
I'll break down each spirit and what they're for in a reply since this is getting too long.