Skip to content

01 - Cloud Concepts and Microsoft 365 Overview

Cloud service models

IaaS - Infrastructure as a Service

You manage: OS, runtime, applications, data. Microsoft manages: physical hardware, virtualization, networking infrastructure. M365 example: Azure Virtual Machines (mostly IaaS, used by some M365 customers for hybrid scenarios).

PaaS - Platform as a Service

You manage: applications, data. Microsoft manages: OS, runtime, middleware, infrastructure. M365 example: Azure App Service.

SaaS - Software as a Service

You manage: data, identity, settings within the app. Microsoft manages: everything else. Most of M365 is SaaS: Exchange Online, SharePoint Online, Teams, Microsoft 365 Apps (web).

Comparison

On-prem:    [App][Data][Runtime][OS][VM][Network][HW]   <- you manage all
IaaS:       [App][Data][Runtime][OS]                    <- you manage above the line
PaaS:       [App][Data]
SaaS:       [Data]                                      <- you only manage data + users

Cloud deployment models

Public cloud

Multi-tenant. Microsoft hosts in shared infrastructure. M365 runs in Microsoft's public cloud (with logical isolation per tenant).

Private cloud

Single-tenant. On-prem datacenter or dedicated cloud hardware. Older banking/government.

Hybrid cloud

Mix of public + private/on-prem. Common for M365 + on-prem AD via Entra Connect.

Multi-cloud

Multiple public clouds (Azure + AWS + GCP). Less common in M365 context but increasingly common in enterprise IT.

Cloud benefits

  • Scalability - scale up/down on demand
  • Elasticity - automatic scaling based on load
  • Agility - deploy in minutes, not months
  • Reliability - cloud SLAs higher than typical on-prem
  • Disaster recovery - geo-redundant by default in M365
  • Predictable costs - subscription pricing
  • Global reach - regional data residency available

Microsoft Cloud

Microsoft's overall cloud portfolio:

  • Microsoft Azure - the public cloud platform (IaaS/PaaS)
  • Microsoft 365 - productivity SaaS suite
  • Dynamics 365 - business apps SaaS (CRM, ERP)
  • Power Platform - low-code (Power BI, Power Apps, Power Automate, Copilot Studio)
  • Microsoft Industry Clouds - vertical SaaS (Healthcare, Financial Services, Retail, Manufacturing, Sustainability, Nonprofit)
  • GitHub - Microsoft-owned, separately branded

M365 sits in this portfolio as the productivity SaaS pillar.

What is Microsoft 365?

The bundle that includes:

  1. Microsoft 365 Apps (Word, Excel, PowerPoint, Outlook, OneNote, Teams, OneDrive, etc.)
  2. Productivity services (Exchange Online, SharePoint Online, Teams, OneDrive)
  3. Windows (in some enterprise tiers)
  4. Enterprise Mobility + Security (EMS) - Entra ID P1/P2, Intune, Defender XDR, Microsoft Purview

M365 vs Office 365

  • Office 365 is the legacy productivity-only bundle (Apps + services, no Windows, no EMS)
  • Microsoft 365 = Office 365 + Windows + EMS = enterprise complete bundle
  • Microsoft is gradually consolidating "Office" branding into "Microsoft 365"

Common SKUs and what's in them

SMB: - Microsoft 365 Business Basic - web/mobile apps + Exchange + Teams + SharePoint - Microsoft 365 Business Standard - desktop apps too - Microsoft 365 Business Premium - + Intune + Defender for Business + Entra ID P1

Enterprise: - Microsoft 365 E3 - apps + services + Intune + Entra ID P1 + Defender for Endpoint P1 - Microsoft 365 E5 - E3 + Defender XDR + Sentinel features + Power BI Pro + Phone System + Audio Conferencing - Microsoft 365 F1/F3 - frontline workers (shift staff, retail floor)

Education: - A1, A3, A5 (analogous to enterprise tiers) - Free for accredited students/faculty (limited features)

Government: - GCC, GCC High, DoD - separate clouds for US government compliance (FedRAMP High, ITAR, IL5)

Microsoft 365 Apps deployment

How apps get to user devices:

  • Click-to-Run - streaming installer; default for M365 apps
  • MSI - legacy installer; use for managed environments needing stricter version control
  • Configuration Manager - SCCM/Intune-managed deployment
  • Direct download - users install from portal

Update channels

Updates come on different cadences:

  • Current Channel - monthly; latest features ASAP
  • Monthly Enterprise Channel - monthly; predictable second-Tuesday cadence
  • Semi-Annual Enterprise Channel - twice a year; for orgs preferring stability
  • Insider channels - beta / dev tracks

Plan deployment by user role: developers and power users on Current; broader workforce on Monthly Enterprise; regulated/managed environments on Semi-Annual.

Tenants

A tenant = your organization's M365 environment.

  • Identified by a domain <name>.onmicrosoft.com (you can also bind verified custom domains)
  • Backed by an Entra ID directory
  • Isolated from other tenants
  • Can be in different regions (data residency)

Multi-tenant

Some orgs (M&A scenarios, multinationals) operate multiple tenants. M365 supports limited cross-tenant scenarios via:

  • Cross-tenant access settings for B2B
  • Cross-tenant synchronization (Entra ID feature)
  • Microsoft 365 Multi-tenant Organizations (newer feature for managing multi-tenant scenarios more cleanly)

Common exam triggers

  • "Office 365 vs Microsoft 365" → M365 includes Windows + EMS; O365 is productivity only
  • "SaaS examples" → Exchange Online, Teams, SharePoint Online, Dynamics 365
  • "Hybrid cloud" → Mix of on-prem + cloud, common with on-prem AD + Entra ID
  • "Geo-redundancy" → Built into M365 by default; data replicated within geo
  • "Update channel for stability" → Semi-Annual Enterprise Channel
  • "Cloud benefit: scaling automatically with load" → Elasticity
  • "Cloud benefit: speed to deploy" → Agility