What is household grain? Please help me

Household grain relationship is the abbreviation of the relationship between household registration and grain and oil.

I won’t talk about the household registration, it’s easy to understand.

The relationship between grain and oil is a bit confusing to today’s young people. Grain, vegetable oil and vegetable oil are everywhere. You can just go to shopping malls, supermarkets, and grain and oil chain stores and buy them directly. Why does it matter? This is because before the 1990s, when my country implemented a planned economy, the supply of grain and oil was tight and it was not possible to maintain open supply. Therefore, planned purchases were implemented, grain and oil coupons and oil stamps were issued, and supplies were provided in fixed quantities per person. Although the grain and oil market is now liberalized, people are still accustomed to using the term consumer-grain relationship.