2. What is Partial generic type?

Utility type Partial accepts any other type or interface. Returned interface contains all fields from original one, but they're all marked as optional.

interface RequiredType {
    name: string,
    age: number
}

type PartialType = Partial<RequiredType>; 

const partialObject: RequiredType = {} // error - name and age are required so must be initialized
const partialObject: PartialType = {} // no error - name and age are optionals so doesn't have to be initialized