The `lateinit` modifier in Kotlin is used to indicate that a non-null property will be initialized at a later point before it is accessed. It is primarily used with mutable properties that cannot be initialized during object construction or immediately upon declaration.

Here's how `lateinit` works :

1. Declaration : The `lateinit` modifier is applied to a `var` property declaration, indicating that it will be initialized later.

   lateinit var name: String​

2. Initialization : The `lateinit` property must be assigned a value before it is accessed, using the assignment operator (`=`).

   name = "John"​

3. Usage: Once the `lateinit` property is initialized, it can be used like any other property.

   println(name)​

It's important to note the following characteristics and considerations when using `lateinit`:

* `lateinit` can only be applied to `var` properties (mutable properties), as it allows the property value to be assigned or changed after initialization.

* `lateinit` can only be used with non-null types, as it implies that the property will eventually be assigned a non-null value.

*  Accessing a `lateinit` property before it is initialized will result in a `lateinit property has not been initialized` exception.

* `lateinit` properties are not thread-safe. If multiple threads can access and modify the property concurrently, appropriate synchronization mechanisms should be used.

* The use of `lateinit` should be limited to cases where the property cannot be assigned a value during object construction and where it is guaranteed to be initialized before accessing it.

* `lateinit` is commonly used in frameworks like dependency injection or when working with certain lifecycle callbacks, where properties need to be initialized by an external entity.