Property vs. Attribute

Attribute	Property
Defined in the HTML markup	Exists on the DOM object
Stored as strings	Can be any JavaScript type
Represents the initial value	Represents the current value
Accessed using getAttribute() / setAttribute()	Accessed using dot notation or bracket notation

<input id="inp" value="Hello">

const input = document.getElementById("inp");

console.log(input.getAttribute("value")); // "Hello"
console.log(input.value); // "Hello"

Now change the value:

input.value = "World";

console.log(input.value); // "World"
console.log(input.getAttribute("value")); // "Hello"