Table of Contents

Cloud Computing: Where Your Software Lives and Runs

A practical guide to cloud infrastructure, providers, and service models.

On-Prem vs Cloud

"On-prem" (on-premises) means you own and manage the physical hardware: servers sitting in your office, a data center you rent, or a co-location facility. Cloud means you rent computing resources from a provider over the internet and pay for what you use.

	On-Prem	Cloud
Hardware	You buy and maintain it	Provider owns it, you rent it
Upfront cost	High (capital expense)	Low (operational expense, pay-as-you-go)
Scaling	Buy more hardware, wait weeks	Click a button, wait minutes
Control	Full control over everything	Limited to what the provider exposes
Maintenance	Your team patches, upgrades, replaces	Provider handles physical infrastructure
Security	You secure everything	Shared responsibility — provider secures infrastructure, you secure your application and data
Location	Data stays in your building	Data lives in provider's data centers (region-selectable)

When on-prem still makes sense:

Strict regulatory or data sovereignty requirements (e.g. government, defense, healthcare in certain jurisdictions)
Workloads with very predictable, constant demand where owning hardware is cheaper long-term
Ultra-low latency requirements where physical proximity to hardware matters
Organizations that already have significant data center investments

When cloud wins:

Variable or unpredictable workloads (scale up for a product launch, scale down after)
Startups and teams that don't want to manage hardware
Global distribution → need servers in multiple regions without building data centers
Speed to market → spin up infrastructure in minutes instead of weeks