Cloud acronyms, decoded

Quick reference

• IaaS — Infrastructure as a Service: you rent raw servers, storage and network, and manage the rest.
• PaaS — Platform as a Service: you push code; the platform runs it, scales it and patches the servers.
• SaaS — Software as a Service: finished software you just log into, like email or a CRM.
• VPC — Virtual Private Cloud: your own isolated network inside the cloud, with your own subnets.
• IAM — Identity and Access Management: who can do what to which resources.
• CDN — Content Delivery Network: copies of your content near users, so it loads fast everywhere.

Explained

IaaS, Infrastructure as a Service. You rent the raw building blocks, virtual servers, storage and networking, and you manage everything on top: the OS, the runtime, your app. EC2 is the classic example. Most control, most responsibility.

PaaS, Platform as a Service. You push your code and the platform runs it: it provisions the servers, scales them, and patches the OS for you. You focus on the app, not the machines. App Engine, Heroku and managed container platforms fit here.

SaaS, Software as a Service. Finished software you simply log into, with nothing to run yourself. Gmail, Salesforce, Microsoft 365. You manage only your data and users.

These three form a ladder: IaaS to PaaS to SaaS, each step handing more responsibility to the provider and leaving you less to manage.

VPC, Virtual Private Cloud. Your own isolated network inside the cloud, where you define subnets, routing and firewall rules. It is how you keep your resources private and segmented.

IAM, Identity and Access Management. Who can do what to which resources. The most important service to get right, and the one attackers exploit when it is too permissive.

CDN, Content Delivery Network. Copies of your static content cached in locations near users worldwide, so pages and files load fast everywhere and your origin server is spared the load.

The cloud is learnable. Behind the acronyms are a few simple ideas.

In one line

The ladder: IaaS -> PaaS -> SaaS: more managed each step