explain JavaScript Retype Password Validation code example

Example: javascript password matching

let pass1 = document.getElementById("pass-one");
    let pass2 = document.getElementById("pass-two");
    let run = document.getElementById("run");

    run.addEventListener("click", function () {
        if (pass1.value !== pass2.value) {
            pass1.style.border = '3px solid red';
            pass2.style.border = '3px solid red';
            run.innerHTML = "Mismatch";
        } else {
            pass1.style.border = '3px solid green';
            pass2.style.border = '3px solid green';
            run.innerHTML = "Matching"
        }
    })