1. "Because TypeScript is a superset of JavaScript, all JavaScript programs are syntactically valid TypeScript, but they can fail to type-check for safety reasons." (Wikipedia: TypeScript, 6.29.23 UTC 12:54)
2. "TypeScript provides static typing through type annotations to enable type checking at compile time. This is optional and can be ignored to use the regular dynamic typing of JavaScript." (Wikipedia: TypeScript, 6.29.23 UTC 12:54)
3. "TypeScript is a language extension that adds features to ECMAScript 6. Additional features include: type annotations and compile-time type checking, type inference, type erasure, interfaces, enumerated types, generics, namespaces, tuples, [and] async/await." (Wikipedia: TypeScript, 6.29.23 UTC 12:54)
