Cloud Computing Glossary 50 Terms You Must Know in 2026

5.  Public cloud     Services offered over the internet to many customers
6.  Private cloud    Cloud-style infrastructure for one organisation
7.  Hybrid cloud     Mix of on-premises and public cloud
8.  Multi-cloud      Using more than one cloud provider
9.  Region           Geographic area with data centres (ap-south-1)
10. Availability Zone One or more isolated data centres in a region
11. Edge location    Site that caches content close to users (CDN)
12. Pay-as-you-go    Billing for what you use
13. Elasticity       Scaling resources up or down with demand
14. High availability Design that keeps running when parts fail

# Which regions and AZs can I use?
aws ec2 describe-regions --query "Regions[].RegionName" --output table
aws ec2 describe-availability-zones --region ap-south-1 \
  --query "AvailabilityZones[].ZoneName" --output text

# Who am I logged in as?
aws sts get-caller-identity

19. AMI / image     Template used to launch servers
20. Container       Packaged app with its dependencies (Docker)
21. Kubernetes      System that runs and manages containers
22. Block storage   Disk volumes attached to servers (EBS)
23. File storage    Shared file system (EFS)
24. Managed database Database run by the provider (RDS)
25. Snapshot        Point-in-time copy of a volume or database
26. Storage class   Price/speed tier for objects (S3 Glacier)
27. Load balancer   Spreads traffic across servers (ALB)
28. Spot instance   Spare capacity at lower price, can be reclaimed

# Object storage: create a bucket and upload a file
aws s3 mb s3://yourname-glossary-demo-2026 --region ap-south-1
aws s3 cp notes.txt s3://yourname-glossary-demo-2026/
aws s3 ls s3://yourname-glossary-demo-2026/

# Serverless: invoke a function you created
aws lambda invoke --function-name hello-glossary out.json
cat out.json

33. CIDR block       IP range notation (10.0.1.0/24)
34. Internet gateway Connects a VPC to the internet
35. NAT gateway      Lets private subnets reach out, not in
36. Route table      Rules for where network traffic goes
37. IAM role         Identity assumed by services or users
38. Policy           JSON document granting permissions
39. MFA              Multi-factor authentication
40. Encryption at rest     Data encrypted on storage (KMS)
41. Encryption in transit  Data encrypted on the network (TLS)
42. Audit log        Record of API actions (CloudTrail)

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": ["s3:GetObject"],
      "Resource": "arn:aws:s3:::yourname-glossary-demo-2026/*"
    }
  ]
}

43. Infrastructure as Code (IaC)
    Defining infrastructure in files (Terraform,
    CloudFormation) so it is repeatable and reviewable.

44. Immutable infrastructure
    Replacing servers with new ones instead of
    changing them in place.

45. Blue-green deployment
    Running two environments and switching traffic
    to the new one after checks pass.

46. RPO (Recovery Point Objective)
    Maximum acceptable data loss, measured in time.

47. RTO (Recovery Time Objective)
    Maximum acceptable time to restore service.

48. FinOps
    Practice of managing and optimising cloud costs
    across engineering and finance teams.

49. Well-Architected Framework
    Provider guidance on reliability, security,
    performance, cost and operations (and
    sustainability) for cloud designs.

50. Landing zone
    A pre-configured multi-account setup with
    security, networking and logging baselines.