What it is: A public/private key pair used to securely connect to EC2 (commonly via SSH).

What it’s for:

• Authenticate SSH access without passwords.
• Secure initial access to instances.

Key ideas:

• You keep the private key; AWS stores the public key.
• Losing the private key can mean losing access (unless you have other access methods).

Exam cues:

• “SSH access to EC2” → key pair + SG rule for port 22.

Hard words:

• *authenticate* /ɔːˈθentɪkeɪt/: xác thực
• *private key* /ˈpraɪvət kiː/: khóa riêng
• *public key* /ˈpʌblɪk kiː/: khóa công khai