What it is: A collection of AWS resources created and managed as a single unit by CloudFormation.

What it’s for:

• Manage resources together (create/update/delete as a unit).
• Keep environments consistent (dev/stage/prod).

Key ideas:

• Stack updates apply changes based on template differences.
• Failed updates can roll back automatically.

Hard words:

• *collection* /kəˈlekʃn/: tập hợp
• *unit* /ˈjuːnɪt/: đơn vị