JavaScript recursive function is interrupted when () is included in a call

Question

I created a Pomodoro countdown timer using JavaScript and jQuery. The code snippet I'm talking about is the following:

var time = 1500;
var cycle = "long";
var tracker = 0;
var paused = false;

//Timer countdown function
function countdown(){
    if (!paused) {

        var seconds = ("00" + (time % 60)).slice(-2);

        $("#time").text(Math.floor(time/60) + ":" + seconds);
        $("title").text(Math.floor(time/60) + ":" + seconds);

        if (time > 0){
        time--;
        setTimeout(countdown, 1000);
        //Once the time is up, determine cycle, play chime and reset timer.
        } else {
            document.getElementById("bell").play();
            tracker++;

            if (tracker == 7) {
                cycle = "long";
                time = 1500;
                setTimeout(countdown, 1000);
            } else if (tracker == 8) {
                time = 1500;
                setTimeout(countdown, 1000);
                tracker = 0;
            } else if (cycle == "short" && tracker < 7) {
                cycle = "long";
                time = 1500;
                setTimeout(countdown, 1000);
            } else if (cycle == "long" && tracker < 7) {
                cycle = "short";
                time = 300;
                setTimeout(countdown, 1000);
            }
        }  
    } else {
        setTimeout(countdown, 1);
    } 
}
setTimeout(countdown(), 1000);

The function calls "setTimeout (countdown, 1000);" located inside the "else" parts of if statements causes a break in the program when it is written as follows: "setTimeout ( countdown () , 1000);" because, as I believe, the function should be called, I am completely puzzled by this and very I appreciate if someone was kind enough to give an explanation.

Question: Why is the program interrupted if "()" is added after the word "countdown"?

Answer 1

setTimeout(countdown(), 1000);, , , JS countdown() inmediatelly. setTimeout(countdown, 1000);, countdown , 1 (1000).

Answer 2

. javascript , . . .