What is Sid attribute use for in key policies?

Question

Here is a documentation:

Sid – (Optional) The Sid is a statement identifier, an arbitrary string you can use to identify the statement.

Does it means that Sid parameter is just description?

Answer 1

In another part of the documentation AWS provides some additional information about the purpose of the Sid:

The Sid (statement ID) is an optional identifier that you provide for the policy statement. You can assign a Sid value to each statement in a statement array. In services that let you specify an ID element, such as SQS and SNS, the Sid value is just a sub-ID of the policy document's ID. In IAM, the Sid value must be unique within a JSON policy.

So yes, it's just a description.