interface

interface Square { 
  color :string, 
  width :number, 
} 

let 네모 :Square = { color : 'red', width : 100 } 

장점: extends가 가능

interface Student {
  name :string,
}
interface Teacher extends Student {
  age :number
}

• type 키워드와의 차이점

interface Animal { 
  name :string 
} 
interface Cat extends Animal { 
  legs :number 
}

type Animal = { 
  name :string 
} 
type Cat = Animal & { legs: number }