What does "next" do inside of .subscribe()?

I have seen three ways to "listen" for changes to a value via an observable / call APIs to fetch data from the backend.

One of these ways has "next:" :

this.MySubscription = this.myService.getStuff().subscribe({
next: (data) => {
<insert code to perform operations with "data">
}, error: (err) => {
console.error(err);
// <insert code for what to do on failure>
}
});


And on the Angular site https://angular.io/guide/observables I see this, with "next(" :

// Call subscribe() to start listening for updates.
const locationsSubscription = locations.subscribe({
next(position) {
console.log('Current Position: ', position);
},
error(msg) {
console.log('Error Getting Location: ', msg);
}
});


But I have been just doing it the "normal way", like this (with no "next"):

this.MySubscription = this.myService.getStuff().subscribe((data: any) => {
<insert code to perform operations with "data">
}, error => {
console.error(error);
<insert code for what to do on failure>
});


Is there any functional difference between these three methods of subscribing? How does each method produce different results?

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