Utility-Types is a library that provides a collection of utility types for TypeScript, complementing the built-in mapped types and aliases. It is designed to be a "lodash" for static types, offering a set of common and additional types that are idiomatic and compatible with TypeScript and Flow's utility types. The library is ideal for TypeScript projects that require type-level operations and transformations, such as creating subsets, intersections, or modifying object properties.