Note$2$: In your discussion of Singletons, address each of the following aspects:

$$ What is a Singleton? $(1)$

$$ Lifecycle of a Singleton.

$$ Define Singletons. $(1)$

A session bean that is created by the container as a single instance for every enterprise application.

$$ The lifecycle of Singletons. $(3)$

Doesn$$t exist $($just give $2$ here$)$

Ready $($give $1.$ Vice versa will still be acceptable$)(6)$