Short answers, pulled from the story.
Economic goods are items requiring effort or resources to produce. This scarcity distinguishes them from free goods like air which exists in unlimited supply for most human needs.
Public goods are both non-rival and non-excludable while private goods prevent other consumers from using them. Examples of public goods include national parks and firework displays whereas food, clothing, cars, and parking spaces fall into the private category.
Elinor Ostrom and her husband Vincent Ostrom proposed modifications in 1977. Their work identified fundamental differences affecting individual incentives and added a fourth type called common-pool resources such as forests, water systems, and the global atmosphere.
An elastic good sees large quantity changes due to small price shifts while inelastic goods have few or no substitutes available. Tickets to major sporting events fit this category and prescription medicine such as insulin remains essential regardless of cost.
Consuming an apple denies another person that specific fruit because private goods prevent other consumers from using them. Stores exclude non-customers who refuse to pay prices and one group catching fish makes them unavailable to others.