What it is: A way to classify AWS services by scope:

• Regional services: exist inside a specific Region.
• Global services: not tied to one Region (work globally).

What it’s for:

• Understand where your resources “live”.
• Design multi-region architectures correctly.
• Avoid mistakes like “why can’t I see my resource in another Region?”

Regional services (typical examples):

• VPC (Region-scoped)
• EC2
• S3 (buckets are in a Region, even though the name is global-unique)
• RDS
• EKS

Global services (typical examples):

• IAM (accounts/users/roles are global in the account)
• Route 53 (global DNS)
• CloudFront (global CDN)

Exam cues:

• “I created it in us-east-1 but can’t find it in ap-southeast-1” → it’s regional.
• “DNS records used worldwide” → global.

Hard words:

• *scope* /skoʊp/: phạm vi
• *tied to* /taɪd tuː/: gắn với
• *unique* /juːˈniːk/: duy nhất