Q17: Route 53 Alias Record vs CNAME Record. - AWS Cloud Architecture

In Simple Words:

CNAME: Standard DNS alias pointing one domain name to another. Cannot be created for the root zone apex (e.g., example.com).
Alias Record: Route 53-specific record that can point the root zone apex (example.com) directly to AWS resources (ALB, CloudFront, S3) with free internal DNS lookups.

hcl

# Alias record at the root zone apex (example.com -> CloudFront):
resource "aws_route53_record" "apex" {
  zone_id = aws_route53_zone.primary.zone_id
  name    = "example.com"
  type    = "A"
  alias {
    name                   = aws_cloudfront_distribution.cdn.domain_name
    zone_id                = aws_cloudfront_distribution.cdn.hosted_zone_id
    evaluate_target_health = false
  }
}