In Typescript, what is the difference between type and interface?

Interfaces can be extended

interface A {
  x: number;
}
interface B extends A {
  y: string;
}

and also augmented

interface C {
  m: boolean;
}
// ... later ...
interface C {
  n: number;
}

Type aliases, however, can represent some things interfaces can't

type NumOrStr = number | string;
type NeatAndCool = Neat & Cool;
type JustSomeOtherName = SomeType;

So in general if you just have a plain object type, as shown in your question, an interface is usually a better approach. If you find yourself wanting to write something that can't be written as an interface, or want to just give something a different name, a type alias is better.

Differences between these too are already in this thread.

type Foo = {
    foo: string
};
interface Foo {
    foo: string;
}

Here type Foo andinterface Foo looks almost similar so its confusing.

interface is contract that the following properties (herefoo:string) should be there in a object. interface is not class. It is used when language does not support Multiple Inheritance. So interface can be a common structure between different classes.

class Bar implements Foo {
    foo: string;
}

let p: Foo = { foo: 'a string' };

Buttype and interface are used in very different context.

let foo: Foo;
let today: Date = new Date();

Here type of foo is Foo and today is Date. Its like a variable decleration which holds the information of typeof other variable. type is like a superset of interfaces, classes, function signature, other types or even values (like type mood = 'Good' | 'Bad'). At the end type describes the possible structure or value of a variable.

It is wrong to say "Interfaces can be implemented" since types can also be implemented

type A = { a: string };


class Test implements A {

    a: string;
}

Although you can do this, you can't implement a type that is a Union of types, which makes totally sense honestly :)

Types is kinda like Interfaces and vice versa: both can implemented by a class. but there are some important differences: 1. when Type is implemented by a class, the properties which belong to the Type must be initialized inside the class, whereas with Interface they must be declared. 2. as @ryan mentioned : Interface can extend another Interface. Types cannot.

type Person = {
    name:string;
    age:number;
}

// must initialize all props - unlike interface
class Manager implements Person {
    name: string = 'John';
    age: number = 55;

    // can add props and methods
    size:string = 'm';
}

const jane : Person = {
    name :'Jane',
    age:46,

    // cannot add more proprs or methods
    //size:'s'
}