What is an offer? The essence of the law of supply? What influences the size of the supply?

Supply is the dependence of the volume of goods of a certain type that manufacturers / sellers are ready to offer on the market for a certain period of time, on the prices at which this product can be sold.
The essence of the law of supply: an increase in prices causes an increase in the number of goods produced / offered for sale, and a decrease in prices causes a decrease in this amount.
The value of the supply is influenced by: First, it is the price of the goods. Second, the prices of substitute and complementary goods and services.

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.