Physical Server in AWS Datacenter A physical server has limited resources. Multiple VMs (EC2 instances) share them. ┌──────────────────────────────────────────────────────────────────────┐ │ Physical Server │ │ │ │ ┌─────────────┐ ┌─────────────┐ ┌─────────────┐ ┌─────────────┐ │ │ │ CPU │ │ Memory │ │ Disk │ │ Network │ │ │ │ 64 cores │ │ 512 GB │ │ 10 TB │ │ 100 Gbps │ │ │ └─────────────┘ └─────────────┘ └─────────────┘ └─────────────┘ │ │ │ │ Hypervisor divides these among VMs │ │ │ │ ┌─────────────┐ ┌─────────────┐ ┌─────────────┐ ┌─────────────┐ │ │ │ EC2 (VM1) │ │ EC2 (VM2) │ │ EC2 (VM3) │ │ EC2 (VM4) │ │ │ │ 2 vCPU │ │ 4 vCPU │ │ 8 vCPU │ │ 2 vCPU │ │ │ │ 8 GB RAM │ │ 16 GB RAM │ │ 32 GB RAM │ │ 8 GB RAM │ │ │ └─────────────┘ └─────────────┘ └─────────────┘ └─────────────┘ │ │ │ └──────────────────────────────────────────────────────────────────────┘ How Resources Are Shared CPU: Time Sharing (Hypervisor Controls) Physical cores are shared by time slicing. Hypervisor decides who runs when. ...

Aurora AWS-managed relational database (MySQL/PostgreSQL compatible) with cloud-native architecture. Storage and compute are separated. Aurora Cluster (Single Region) One primary instance (read/write) + optional read replicas sharing the same storage. Writer Endpoint Reader Endpoint │ │ ▼ ▼ ┌──────────────┐ ┌──────────────┬──────────────┐ │ Primary │ │ Replica 1 │ Replica 2 │ │ (Writer) │ │ (Reader) │ (Reader) │ └──────┬───────┘ └──────┬───────┴──────┬───────┘ │ │ │ └─────────────┬───────────────┴──────────────┘ ▼ ┌────────────────────────────────────────┐ │ Shared Cluster Storage │ │ (6 copies across 3 AZs) │ │ Auto-grows up to 128 TB │ └────────────────────────────────────────┘ All instances share same storage (no replication lag for storage) Replicas can be promoted to primary if primary fails (~30 seconds failover) Up to 15 read replicas Single region only Aurora Storage One logical storage automatically replicated across 3 AZs (6 copies total, 2 per AZ). ...

Summary: The Complete Journey Your PC (192.168.1.10) │ │ Create HTTP request │ Encode UTF-8 → Compress → Encrypt (TLS) ▼ ┌─────────────────────────────────────────┐ │ Ethernet: Dest=Router MAC │ │ IP: Dest=142.250.190.14 (Google) │ │ TCP: Dest Port=443 │ │ TLS: Encrypted HTTP data │ └─────────────────────────────────────────┘ │ ▼ Your Router (NAT: private → public IP) │ ▼ ISP Routers (forward based on IP) │ ▼ Google Edge Router (forward to internal) │ ▼ Google Load Balancer (NAT: public → private server IP) │ ▼ Google Server (10.0.0.20) │ │ Decrypt → Decompress → Decode │ Process HTTP request ▼ Response travels back the same way What is the OSI Model? A theoretical 7-layer model that describes how data moves from an application to physical transmission. Created in 1984 to standardize network communication. ...