AWS Information doc

AWS/1-Information.md

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+# AWS Core Services Overview
+
+## Compute & Container Services
+
+**EC2 (Elastic Compute Cloud)**
+
+* Infrastructure as a Service (IaaS)
+* Provides virtual machines (instances)
+* Storage options:
+
+  * **EBS** (Elastic Block Store): High-performance block storage attached to a single instance
+  * **EFS** (Elastic File System): Network file system that can be mounted by multiple instances
+* Requires user management of OS, patching, and scaling
+
+**ECS (Elastic Container Service)**
+
+* AWS-managed container orchestration service
+* Supports Docker containers
+* Deployment options:
+
+  1. **EC2 Launch Type** – you manage EC2 instances
+  2. **Fargate Launch Type** – serverless, AWS manages infrastructure
+
+**ECR (Elastic Container Registry)**
+
+* Fully managed Docker container image registry
+* Used to store, manage, and deploy container images for ECS and EKS
+
+**EKS (Elastic Kubernetes Service)**
+
+* Managed Kubernetes service
+* AWS manages the Kubernetes control plane
+* Worker nodes can run on EC2 or Fargate
+
+**AWS Lambda**
+
+* Serverless compute service
+* Event-driven execution
+* Maximum execution time: **15 minutes**
+* No server management required
+* Common use cases: APIs, background jobs, automation
+
+---
+
+## Messaging & Integration
+
+**SQS (Simple Queue Service)**
+
+* Fully managed message queue service
+* Used for decoupling and scaling distributed systems
+* Supports Standard and FIFO queues
+
+---
+
+## Databases
+
+**RDS (Relational Database Service)**
+
+* Managed relational databases (MySQL, PostgreSQL, Oracle, SQL Server, MariaDB, Aurora)
+* Typically deployed in **private subnets**
+* High availability using Multi-AZ
+* Automated backups, patching, and scaling
+
+**DynamoDB**
+
+* Fully managed NoSQL key-value and document database
+* Serverless, auto-scaling, and highly available
+* Low latency and global replication support
+
+---
+
+## Networking & Traffic Management
+
+**VPC (Virtual Private Cloud)**
+
+* Isolated virtual network in AWS
+* Uses CIDR ranges for IP addressing
+
+**Subnets**
+
+* **Public Subnet**: Has a route to the Internet Gateway
+* **Private Subnet**: No direct internet access
+
+**Internet Gateway (IGW)**
+
+* Enables inbound and outbound internet access for public subnets
+
+**NAT Gateway**
+
+* Placed in a public subnet
+* Allows **outbound-only** internet access for private subnet resources
+* Cannot receive inbound connections
+
+**Route 53**
+
+* Managed DNS service
+* Supports domain registration, routing policies, and health checks
+
+---
+
+## Load Balancing
+
+**ELB (Elastic Load Balancing)**
+
+* Distributes traffic across multiple targets
+
+**ALB (Application Load Balancer)**
+
+* Layer 7 (Application layer)
+* Supports HTTP/HTTPS routing rules
+* Can route traffic to:
+
+  * EC2
+  * ECS
+  * Lambda
+  * IP addresses
+
+---
+
+## Security & Identity
+
+**IAM (Identity and Access Management)**
+
+* Manages users, groups, roles, and permissions
+* Global AWS service
+
+**IAM Roles**
+
+* Used by AWS services to access other AWS resources securely
+
+**IAM Reports**
+
+* **Credential Report**: Shows credential status for all users
+* **Access Advisor**: Shows last-used service permissions
+
+**Security Groups**
+
+* Stateful virtual firewalls for AWS resources
+* Control inbound and outbound traffic
+* Attached to EC2, ALB, RDS, ECS, etc.
+
+---
+
+## Monitoring & Logging
+
+**CloudWatch**
+
+* Monitoring and observability service
+* Collects metrics, logs, and events
+* Used for alarms, dashboards, and automation
+
+---
+
+## AWS Global Infrastructure
+
+**Region**
+
+* Geographic area containing multiple Availability Zones
+
+**Availability Zone (AZ)**
+
+* One or more isolated data centers within a region
+
+**Global Services**
+
+* IAM
+* Route 53
+* CloudFront
+* AWS WAF
+
+**Regional Services**
+
+* EC2
+* ECS
+* EKS
+* RDS
+* Lambda
+
+---
+
+## IP Addressing
+
+**Private IP**
+
+* Assigned from VPC CIDR range
+* Used for internal communication
+
+**Public IP**
+
+* Assigned automatically to EC2 instances in public subnets
+* Released when instance is stopped
+
+**Elastic IP (EIP)**
+
+* Static public IPv4 address
+* Remains allocated even if the instance stops
+* Used for failover and stable endpoints
+
+---
+
+## Database Networking Best Practices
+
+* RDS instances should run in **private subnets**
+* Access options:
+
+  * EC2 in the same VPC
+  * Bastion host
+  * VPN or Direct Connect
+* NAT Gateway can be used for outbound access (updates, patches)