I don't understand why I got a bill

When you terminate an EC2 instance, you stop incurring charges for the instance itself, but there are often associated resources that continue to generate costs even after the instance is deleted. Common resources that remain and continue billing include EBS volumes (storage attached to the instance), Elastic IP addresses that aren't associated with a running instance, snapshots, and other AWS services that were used alongside the instance. Since you terminated your instance at the end of June, your next bill would include charges for the full month of June when the instance was still running, plus any ongoing charges from these associated resources. I recommend checking your AWS Cost Explorer or billing dashboard to identify which specific resources are generating the charges. Look particularly for any EBS volumes, unattached Elastic IPs, or snapshots that may have been created from that instance. You can delete these resources through the EC2 console to stop future charges. Additionally, you can set up billing alerts in your AWS account to notify you when charges exceed certain thresholds, which can help you catch unexpected costs more quickly in the future.