# Constants declared with const

A variable declared with `const` can be *mutable* or *immutable* depending on the data type of the assigned value. However, a *constant* cannot be reassigned to a new value.

The difference between assignment and immutability (mutability) is:

* The **assignment** has to do with variable bindings, binding a name to a piece of data.
    
* **Immutability (mutability)** is a property that belongs to the actual data that the binding contains. All primitives (strings, numbers, and so on) are immutable, whereas objects are mutable.
    

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1687440032717/0d1bb52e-20e6-455b-9e04-300093a795a2.png align="center")

To summarize, when we say constants are immutable, we mean that once a primitive value is assigned to a constant, it cannot be changed. And when we say constants are not immutable, we mean that we can change the properties of the non-primitive values like objects, arrays, etc.