They build new string literal types by combining other literal types using template syntax (e.g., `user_${"id" | "name"}`).
Advanced answer
Deep dive
Expanding on the short answer — what usually matters in practice:
Context (tags): template-literal, types
Explain the "why", not just the "what" (intuition + consequences).
Trade-offs: what you gain/lose (time, memory, complexity, risk).
Edge cases: empty inputs, large inputs, invalid inputs, concurrency.
Examples
A tiny example (an explanation template):
// Example: discuss trade-offs for "what-are-template-literal-types?"
function explain() {
// Start from the core idea:
// They build new string literal types by combining other literal types using template syntax
}
Common pitfalls
Too generic: no concrete trade-offs or examples.
Mixing average-case and worst-case (e.g., complexity).