obs stands for "observable." It's a part of GetX's reactive programming paradigm that allows you to create reactive variables and update the UI automatically whenever these variables change.

The obs modifier converts a variable into a reactive object. When the value of the observed object changes, it automatically triggers a re-rendering of the UI that relies on that object.

1. Primitive types:

import 'package:get/get.dart';

void main() {
  var count = 0.obs; // Making count observable
  print(count.value); // Accessing the value of the observable
  count.value++; // Updating the value of the observable
}

2. List:

import 'package:get/get.dart';

void main() {
  var myList = <String>[].obs; // Making a List observable
  myList.add('Hello'); // Updating the observable List
}

3. Map:

import 'package:get/get.dart';

void main() {
  var myMap = <String, int>{}.obs; // Making a Map observable
  myMap['key'] = 10; // Updating the observable Map
}

4. Custom class:

import 'package:get/get.dart';

class Person {
  var name = 'John'.obs; // Making a property of a custom class observable
}

void main() {
  var person = Person();
  print(person.name.value); // Accessing the value of the observable property
  person.name.value = 'Alice'; // Updating the value of the observable property
}