Object

In React JS and JavaScript, an 'Object' is a standalone entity with properties and types. You can think of an object as a 'box' that holds related data and functionality. It resembles real-world objects like a car or a person, having properties and behaviors.

Properties are characteristics of an object, while methods are tasks that an object can perform. A JavaScript object is a hashmap or a collection of key-value pairs. Here, the properties are the keys and can be of any JavaScript data type, including arrays and objects.

In ReactJS, an object might be used to represent a component state, or properties (props) passed into a component.

Here's an example of a simple JavaScript object:

```
var student = {
firstName: "Harry",
lastName: "Potter",
age: 11,
house: "Gryffindor",
};
```

In this example object, 'student', there are four properties: firstName, lastName, age, and house. Each of these properties have a value assigned to them.

Here's an example of an object used for the state in React component:

```
class Student extends React.Component {
constructor(props) {
super(props);
this.state = {
firstName: 'Harry',
lastName: 'Potter',
age: 11,
house: 'Gryffindor',
};
}

// ...
}
```

In this case, the 'state' object represents the state of a "Student" component, with properties for 'firstName', 'lastName', 'age', and 'house'. This state object would then be used to handle the internal state/data of the Student component in your React application.