Question: How do I understand the configurationItemDiff field in Amazon SNS ConfigurationItemChangeNotification notifications?

I received a ConfigurationItemChangeNotification Amazon Simple Notification Service (Amazon SNS) notification. Why did I get this notification, and how do I interpret the information in the configurationItemDiff field?ResolutionAWS Config creates a configuration item whenever the configuration of a resource changes (create/update/delete). For a list of resources that AWS Config supports, see Supported resource types. AWS Config uses Amazon SNS to deliver a notification as the changes occur. The Amazon SNS notification payload includes fields to help you track the resource changes in a given AWS Region. For more information, see Example configuration item change notifications.To understand why you receive a ConfigurationItemChangeNotification notification, review the configurationItemDiff details. The fields vary depending on the change type and can form different combinations such as UPDATE-UPDATE, UPDATE-CREATE, and DELETE-DELETE. The following are explanations of some common combinations.UPDATE-CREATE and UPDATE-UPDATEThe following example includes changes in the resource direct relationships and resource configurations. The configurationItemDiff details reveal the following information:Action performed: A managed policy present in the account was attached to an AWS Identity and Access Management (IAM) role.Basic operation performed: UPDATE (updating the number of associations of the resource type AWS::IAM::Policy in an account).Change type combinations:Resource direct relationship change UPDATE-CREATE. A new attachment or association was created between an IAM policy and an IAM role.Resource configuration change UPDATE-UPDATE. The number IAM policy associations increased from 2 to 3 when the policy was attached to the IAM role.Example UPDATE-CREATE and UPDATE-UPDATE configurationItemDiff notification:{    "configurationItemDiff": {        "changedProperties": {            "Relationships.0": {                "previousValue": null,                "updatedValue": {                    "resourceId": "AROA6D3M4S53*********",                    "resourceName": "Test1",                    "resourceType": "AWS::IAM::Role",                    "name": "Is attached to Role"                },                "changeType": "CREATE"                >>>>>>>>>>>>>>>>>>>> 1            },            "Configuration.AttachmentCount": {                "previousValue": 2,                "updatedValue": 3,                "changeType": "UPDATE"                 >>>>>>>>>>>>>>>>>>>> 2            }        },        "changeType": "UPDATE"    }}UPDATE-DELETEThe following example includes changes in the resource direct relationships. The configurationItemDiff details reveal the following information:Action performed: A managed policy present in the account was detached from an IAM user.Basic operation performed: UPDATE (updating the permissions policy associated with the resource type AWS::IAM::User).Change type combination: Resource direct relationship change UPDATE-DELETE. The association between an IAM user and an IAM policy in an account was deleted.Example UPDATE-DELETE configurationItemDiff notification:{  "configurationItemDiff": {    "changedProperties": {      "Configuration.UserPolicyList.0": {        "previousValue": {          "policyName": "Test2",          "policyDocument": "{    "Version": "2012-10-17",    "Statement": [        {            "Sid": "VisualEditor0",            "Effect": "Allow",            "Action": "ec2:RunInstances",            "Resource": "arn:aws:ec2:*:*:instance/*",            "Condition": {                "StringLike": {                    "aws:RequestTag/VPCId": "*"                }            }        }    ]}"        },        "updatedValue": null,        "changeType": "DELETE"                                >>>>>>>>>>>>>>>>>>>> 3      }    },    "changeType": "UPDATE"  }}DELETE-DELETEThe following example includes changes in the resource direct relationships and resource configurations. The configurationItemDiff details reveal the following information:Action performed: An IAM role present in an account was deleted.Basic operation performed: DELETE (a resource of the resource type AWS::IAM::Role was deleted).Change type combination: Resource direct relationship change and resource configuration change DELETE-DELETE. The deletion of the IAM role also deleted the association of the IAM policy with the IAM role.Example DELETE-DELETE configurationItemDiff notification:{  "configurationItemDiff": {    "changedProperties": {      "Relationships.0": {        "previousValue": {          "resourceId": "ANPAIJ5MXUKK*********",          "resourceName": "AWSCloudTrailAccessPolicy",          "resourceType": "AWS::IAM::Policy",          "name": "Is attached to CustomerManagedPolicy"        },        "updatedValue": null,        "changeType": "DELETE"      },      "Configuration": {        "previousValue": {          "path": "/",          "roleName": "CloudTrailRole",          "roleId": "AROAJITJ6YGM*********",          "arn": "arn:aws:iam::123456789012:role/CloudTrailRole",          "createDate": "2017-12-06T10:27:51.000Z",          "assumeRolePolicyDocument": "{"Version":"2012-10-17","Statement":[{"Sid":"","Effect":"Allow","Principal":{"AWS":"arn:aws:iam::123456789012:root"},"Action":"sts:AssumeRole","Condition":{"StringEquals":{"sts:ExternalId":"123456"}}}]}",          "instanceProfileList": [],          "rolePolicyList": [],          "attachedManagedPolicies": [            {              "policyName": "AWSCloudTrailAccessPolicy",              "policyArn": "arn:aws:iam::123456789012:policy/AWSCloudTrailAccessPolicy"            }          ],          "permissionsBoundary": null,          "tags": [],          "roleLastUsed": null        },        "updatedValue": null,        "changeType": "DELETE"      }    },    "changeType": "DELETE"  }Related informationNotifications that AWS Config sends to an Amazon SNS topic