Short answers, pulled from the story.
Economic goods are scarce, meaning producing them requires expending effort or resources. Free goods, such as the Earth's atmosphere or seawater, have an unlimited supply and therefore no monetary value despite being useful.
The four types are public goods (non-rival and non-excludable, such as national parks), private goods (rivalrous and excludable, such as food and clothing), common-pool resources (rivalrous but non-excludable, such as fisheries), and club goods (excludable but non-rivalrous, such as cable television).
A bad, also called a discommodity, is the opposite of a good: its presence or consumption has negative utility and a negative price. A household paying a waste collector to remove garbage is the standard example, because both the money and the garbage move toward the collector.
In 1977, Elinor Ostrom and Vincent Ostrom proposed replacing "rivalry of consumption" with "subtractability of use," treating excludability and subtractability as continuous scales rather than binary properties, explicitly adding common-pool resources as a fourth category, and renaming club goods as toll goods.
Final goods are items ultimately consumed by an end user, such as a microwave oven or a bicycle. Intermediate goods, such as textiles or transistors, are used in the production of other goods rather than consumed directly. Capital goods are durable items, such as machinery or ecosystems, that are used to produce further goods.
Marginal utility is the change in pleasure or satisfaction gained by consuming one additional unit of a good. Goods are commonly understood to have diminishing marginal utility, meaning each successive unit consumed adds less satisfaction than the previous one.