Terraform records information about what infrastructure it created in a Terraform state file.
State file contains a custom JSON format that records a mapping from the Terraform resources in configuration files to the resources on the account.
Every time Terraform runs, it can fetch the latest status of the resource and compare it to what’s in the Terraform configuration to determine what changes need to be applied. In other words, the output of the plan command is a diff between the code on your computer and the infrastructure deployed in the real world, as discovered via IDs in the state file.
Warning
The state file is a private API that is meant only for internal use within Terraform. Do not edit it manually.
Example
resource "aws_instance" "example" {
ami = "ami-0fb653ca2d3203ac1"
instance_type = "t2.micro"
}{
"version": 4,
"terraform_version": "1.2.3",
"serial": 1,
"lineage": "86545604-7463-4aa5-e9e8-a2a221de98d2",
"outputs": {},
"resources": [
{
"mode": "managed",
"type": "aws_instance",
"name": "example",
"provider": "provider[\"registry.terraform.io/hashicorp/aws\"]",
"instances": [
{
"schema_version": 1,
"attributes": {
"ami": "ami-0fb653ca2d3203ac1",
"availability_zone": "us-east-2b",
"id": "i-0bc4bbe5b84387543",
"instance_state": "running",
"instance_type": "t2.micro",
"(...)": "(truncated)"
}
}
]
}
]
}