# Step 1: Azure Services Index — Complete Reference

> Comprehensive index of Azure services across IaaS, PaaS, and SaaS.
> For Azure Solution Architect interview prep.

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## 🏗️ IaaS — Infrastructure as a Service

### Compute
| Service | What It Does |
|---|---|
| **Virtual Machines (VMs)** | Linux/Windows VMs on demand. Your bread and butter IaaS. |
| **VM Scale Sets** | Auto-scaling groups of identical VMs for load balancing & HA |
| **Azure VMware Solution** | Run VMware natively on Azure (migration path for VMware shops) |
| **Azure Dedicated Host** | Single-tenant physical servers — you own the hardware, Azure runs the DC |
| **Azure Bastion** | Managed RDP/SSH access to VMs without public IPs (PaaS-ish but IaaS adjacent) |
| **Azure Compute Gallery** | Managed VM image sharing across regions/subscriptions |
| **Azure Spot VMs** | Discounted VMs using unused capacity — can be evicted anytime |
| **Azure Reserved VM Instances** | 1-3 year commitments for significant discounts |

### Networking
| Service | What It Does |
|---|---|
| **Virtual Network (VNet)** | Your private network in Azure. Everything connects here. |
| **VNet Peering** | Connect VNets (same or different regions/subscriptions) |
| **VPN Gateway** | Site-to-site, point-to-site, VNet-to-VNet VPN |
| **ExpressRoute** | Private dedicated connection to Azure (no public internet) |
| **Load Balancer** | L4 load balancing (public & internal) |
| **Application Gateway** | L7 load balancer with WAF, SSL termination, URL-based routing |
| **Azure Firewall** | Managed cloud-native firewall (L3-L7) |
| **Azure Firewall Manager** | Centralized firewall policy management |
| **NAT Gateway** | Outbound NAT for SNAT — fixed public IP for outbound |
| **Network Security Groups (NSGs)** | L3/L4 firewall rules on subnets/NICs |
| **Application Security Groups (ASGs)** | Group VMs by workload for simpler NSG rules |
| **Route Tables (UDR)** | Custom routing — control where traffic goes |
| **Azure DNS** | DNS hosting for your domains |
| **Private DNS Zones** | DNS for private endpoints / internal resolution |
| **Private Link / Private Endpoint** | Access PaaS services over private IPs (no public exposure) |
| **Front Door** | Global L7 load balancer / CDN with WAF |
| **Traffic Manager** | DNS-based global traffic routing |
| **CDN** | Content delivery network (Akamai, Verizon, Microsoft) |
| **Azure Virtual WAN** | Unified global networking (branch connectivity) |
| **Network Watcher** | Network monitoring, diagnostics, packet capture |
| **Azure Internet Analyzer** | Test networking changes before going live |
| **IP Addresses** | Public & private static IPs |
| **DDoS Protection** | Basic (free) & Standard (paid) DDoS mitigation |

### Storage
| Service | What It Does |
|---|---|
| **Blob Storage** | Object storage — block blobs, append blobs, page blobs |
| **Managed Disks** | Persistent storage for VMs (Premium SSD, Standard SSD, Standard HDD, Ultra Disk) |
| **Azure NetApp Files** | Enterprise NFS/SMB file shares (NetApp on Azure) |
| **Azure Elastic SAN** | SAN-like storage for workloads needing high IOPS |

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## ⚙️ PaaS — Platform as a Service

### Compute (App Hosting)
| Service | What It Does |
|---|---|
| **App Service** | Web apps, mobile backends, API apps, containers — fully managed |
| **App Service Environments (ASE)** | Isolated App Service for compliance / high scale |
| **Azure Functions** | Serverless compute — event-driven, pay-per-execution |
| **Azure Container Apps** | Serverless containers with KEDA scaling (built on K8s but no cluster management) |
| **Azure Kubernetes Service (AKS)** | Managed Kubernetes — you manage pods, Azure manages control plane |
| **Container Instances (ACI)** | Run a container without orchestrating — quick & simple |
| **Azure Red Hat OpenShift (ARO)** | Managed OpenShift on Azure |
| **Static Web Apps** | Static site + serverless APIs (CI/CD built in) |
| **Azure Spring Apps** | Managed Spring Boot microservices |

### Databases
| Service | What It Does |
|---|---|
| **Azure SQL Database** | Managed SQL Server (single db, elastic pool, managed instance) |
| **Azure SQL Managed Instance** | Near-100% SQL Server compatibility — migration friendly |
| **Azure Database for PostgreSQL** | Managed PostgreSQL (flexible server, single server) |
| **Azure Database for MySQL** | Managed MySQL (flexible server) |
| **Azure Database for MariaDB** | Managed MariaDB |
| **Cosmos DB** | Multi-model NoSQL — global distribution, 5 APIs (SQL, MongoDB, Cassandra, Gremlin, Table) |
| **Azure Cache for Redis** | Managed Redis cache |
| **Azure Synapse Analytics** | Data warehouse + analytics (formerly SQL DW) |
| **Azure Databricks** | Apache Spark-based analytics platform |
| **Data Explorer (Kusto)** | Log & telemetry analytics (ADL) |

### Storage & Data
| Service | What It Does |
|---|---|
| **Azure Files** | Managed SMB/NFS file shares (mount anywhere) |
| **Azure Data Lake Storage (ADLS Gen2)** | Hadoop-compatible data lake on Blob Storage |
| **Azure Table Storage** | NoSQL key-value store (cheap, simple) |
| **Azure Queue Storage** | Message queue for async communication |
| **Azure Data Box** | Physical device for offline data transfer (TB-PB scale) |

### Messaging & Integration
| Service | What It Does |
|---|---|
| **Service Bus** | Enterprise message broker — queues, topics, sessions |
| **Event Grid** | Event routing — reactive, pub/sub |
| **Event Hubs** | Big data streaming ingest (Kafka-compatible) |
| **Azure Relay** | Hybrid connectivity — expose on-prem services to cloud |
| **API Management (APIM)** | Publish, secure, analyze APIs — gateway + portal + management |
| **Logic Apps** | Workflow automation — visual, 200+ connectors |
| **Azure API for FHIR** | Healthcare data interoperability |

### AI / ML
| Service | What It Does |
|---|---|
| **Azure OpenAI** | GPT-4, GPT-3.5, DALL-E, Whisper — Azure-hosted OpenAI models |
| **Azure AI Services (Cognitive Services)** | Vision, Speech, Language, Decision, Search — pre-built AI APIs |
| **Azure Machine Learning** | End-to-end ML platform — train, deploy, manage models |
| **Azure Databricks** | Spark-based ML & analytics |
| **Bot Service** | Build & host conversational bots |
| **Azure AI Search** (formerly Cognitive Search) | AI-powered search over your data |

### Analytics
| Service | What It Does |
|---|---|
| **Azure Synapse Analytics** | Unified analytics (SQL + Spark + Pipelines + Studio) |
| **Azure Stream Analytics** | Real-time stream processing (SQL-like queries) |
| **Azure Data Factory** | ETL / data integration — orchestrate data movement |
| **HDInsight** | Managed Hadoop, Spark, Kafka, Storm, HBase |
| **Analysis Services** | Enterprise OLAP / semantic modeling |
| **Power BI Embedded** | Embed BI in your apps |
| **Azure Purview** | Data governance & catalog |

### Developer Tools
| Service | What It Does |
|---|---|
| **Azure DevOps** | Boards, Repos, Pipelines, Test Plans, Artifacts — ALM suite |
| **GitHub Enterprise (Azure)** | GitHub integration for Azure |
| **Azure Monitor** | Logs, metrics, alerts, dashboards — observability platform |
| **Application Insights** | APM — part of Monitor, for app performance |
| **Log Analytics** | Query logs with Kusto (KQL) — part of Monitor |
| **Azure Key Vault** | Secrets, keys, certificates management |
| **Azure Managed HSM** | Hardware security module for cryptographic keys |
| **App Configuration** | Centralized app config + feature flags |

### Identity & Access
| Service | What It Does |
|---|---|
| **Microsoft Entra ID** (Azure AD) | Cloud identity — SSO, MFA, conditional access, B2B, B2C |
| **Microsoft Entra External ID** | CIAM — customer identity (was Azure AD B2C) |
| **Microsoft Entra Domain Services** | Managed domain services (LDAP, Kerberos, NTLM) |
| **Microsoft Entra Verified ID** | Decentralized identity / verifiable credentials |
| **Microsoft Entra Permissions Management** | CIEM — manage permissions across clouds |

### Security
| Service | What It Does |
|---|---|
| **Microsoft Defender for Cloud** | CSPM + workload protection (was Security Center + Defender) |
| **Microsoft Sentinel** | Cloud-native SIEM + SOAR |
| **Azure Key Vault** | Secrets, keys, certs (listed above, but security-critical) |
| **Azure Attestation** | Remote attestation of TEEs (trusted execution environments) |
| **Azure Confidential Computing** | Encrypt data in use — TEE-based VMs |
| **Azure Dedicated HSM** | FIPS 140-2 Level 3 HSM (Thales) |
| **Azure Policy** | Enforce org rules & compliance at scale |
| **Azure Blueprints** | Package of policies + RBAC + ARM templates for compliance |
| **Microsoft Defender for Storage/SQL/App Service/etc.** | Workload-specific threat protection |
| **Microsoft Defender for IoT** | IoT/OT security |
| **Azure Web Application Firewall (WAF)** | Web app protection (on App Gateway / Front Door) |

### Management & Governance
| Service | What It Does |
|---|---|
| **Azure Resource Manager (ARM)** | Deployment & management layer — everything goes through ARM |
| **ARM Templates / Bicep** | IaC — declarative resource deployment |
| **Azure Portal** | Web UI |
| **Azure CLI / PowerShell / SDKs** | Programmatic management |
| **Azure Advisor** | Personalized best-practice recommendations |
| **Azure Cost Management** | Track, allocate, optimize spend |
| **Azure Lighthouse** | Multi-tenant management (MSP scenario) |
| **Azure Arc** | Manage on-prem / multi-cloud resources from Azure |
| **Azure Migrate** | Assessment & migration tool for on-prem workloads |
| **Microsoft Cloud for Sovereignty** | Sovereign cloud offerings |

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## 📦 SaaS — Software as a Service

### Productivity & Collaboration
| Service | What It Does |
|---|---|
| **Microsoft 365** | Office apps + cloud services (Exchange, SharePoint, Teams, OneDrive) |
| **Microsoft Teams** | Chat, meetings, collaboration |
| **SharePoint Online** | Document management & intranet |
| **OneDrive for Business** | Cloud file storage |
| **Exchange Online** | Email & calendar |
| **Microsoft Viva** | Employee experience platform |

### Business Applications
| Service | What It Does |
|---|---|
| **Dynamics 365** | ERP + CRM suite (Sales, Finance, Supply Chain, etc.) |
| **Power Platform** | Power Apps, Power Automate, Power BI, Power Virtual Agents |
| **Microsoft Fabric** | Unified analytics platform (lakehouse, data warehouse, real-time analytics) |

### Industry & Vertical SaaS
| Service | What It Does |
|---|---|
| **Microsoft Cloud for Healthcare** | Healthcare-specific solutions |
| **Microsoft Cloud for Financial Services** | FSI-specific solutions |
| **Microsoft Cloud for Retail** | Retail-specific solutions |
| **Microsoft Cloud for Manufacturing** | Manufacturing-specific solutions |
| **Microsoft Cloud for Sustainability** | ESG reporting & management |
| **Microsoft Cloud for Nonprofit** | Nonprofit-specific solutions |

### Dev & Ops SaaS
| Service | What It Does |
|---|---|
| **GitHub (SaaS)** | Code hosting, CI/CD, Copilot |
| **Visual Studio / VS Code (cloud features)** | Dev tools with cloud-connected services |
| **Microsoft Defender for Cloud Apps** (MCAS) | CASB — discover, control, protect SaaS apps |
| **Windows 365** | Cloud PC — streamed Windows desktop |

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## 🔀 Hybrid & Edge (Cross-Model)

| Service | What It Does |
|---|---|
| **Azure Arc** | Manage on-prem / multi-cloud from Azure (K8s, SQL, VMs) |
| **Azure Stack HCI** | Hyper-converged infrastructure on-prem, managed from Azure |
| **Azure Stack Hub** | Run Azure services on-prem (disconnected possible) |
| **Azure Stack Edge** | Edge computing device with AI/ML + storage |
| **Azure IoT Hub** | IoT device management & communication |
| **Azure IoT Edge** | Run cloud workloads on edge devices |
| **Azure Digital Twins** | IoT spatial intelligence graph |
| **Azure Sphere** | Secured MCU for IoT devices |
| **Azure RTOS** | Real-time OS for IoT |

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## 🗺️ How to Read This for Interview Prep

**Must-know for Solution Architect:**
- VNet, NSG, Private Link, ExpressRoute, VPN Gateway
- VMs, App Service, AKS, Functions
- Azure SQL, Cosmos DB, Redis
- Storage (Blob, Files, Managed Disks)
- Service Bus, Event Grid, Event Hubs
- Microsoft Entra ID, Key Vault, Azure Policy, RBAC
- ARM/Bicep, Azure Monitor, Log Analytics
- Azure Migrate, Azure Arc
- Microsoft Defender for Cloud, Sentinel

**Nice-to-know (differentiator):**
- Azure Front Door vs App Gateway (when to use which)
- Cosmos DB consistency levels & API choices
- ASE vs App Service (isolation requirements)
- ExpressRoute vs VPN (tradeoffs)
- Private Link architecture patterns
- Azure Well-Architected Framework pillars

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*Next: Step 2 — Role-specific deep dives*
