The 'this' keyword in Javascript refers to the object it belongs to, and depending how it is called will log differently.

If you log 'this' alone it refers to the global object, and will access the browser window object.
Give it a go in your developer tools and see what happens.
This is rarely needed and should be avoided.

In an object method, it refers to the properties of the object. For example:

let person = {
name: 'Chloe',
DOB: 1993,
citizenship: 'United Kingdom',
describe(){
console.log(`${this.name} was born in ${this.citizenship}.)
};
};
person.describe() => Chloe was born in the United Kingdom.