If you’re unfamiliar with what alcohol extraction has to do with weed, here is a quick entry with encyclopedic knowledge on everything you’d ever want or need to know.
Alcohol Extraction Overview
Alcohol extraction is a process of removing essential oils, fats, and other chemical compounds from plants. Any plant as a matter of fact. Alcohol extraction is by no means exclusive to cannabis.
However, of the many possible ways to use alcohol to extract material from plants, only a few work well with cannabis. This is because of the unique chemistry of the desirable compounds in cannabis. The extreme delicacy of the terpenes in cannabis also limits viable extraction to just a few methods.
The most common is butane extraction.
... read more at: https://www.greenrushdaily.com/alcohol-extraction/