Objects inherit from other objects via the prototype chain. Property lookups walk up the chain until found or null. You can create links with Object.create or class syntax.
Expanding on the short answer — what usually matters in practice:
A tiny example (an explanation template):
// Example: discuss trade-offs for "explain-prototypal-inheritance-in-javascript."
function explain() {
// Start from the core idea:
// Objects inherit from other objects via the prototype chain. Property lookups walk up the c
}