Can you list the main types of objects in Kotlin and explain their differences?

In Kotlin, the main types of objects and their differences:

• Classes (class) — templates for creating objects with state and behavior. They can have constructors, properties, methods.

• Objects (object) — singletons, i.e., a single instance of a class created automatically. Used for storing global state or utilities.

• Companion objects (companion object) — an object inside a class that allows creating static members (similar to static in Java).

• Data classes (data class) — classes designed for storing data. Automatically generate methods like equals, hashCode, toString, copy.

• Sealed classes (sealed class) — a limited set of subclasses, useful for expressing hierarchies with a fixed number of options.

• Enum classes (enum class) — enumerations, a set of named constants.

Example of an object and a companion:

object Singleton {
    val name = "I am a singleton"
}

class MyClass {
    companion object {
        fun create() = MyClass()
    }
}

Objects are created once and used as global instances, while classes can have multiple instances.