Cloud service models (IaaS, PaaS, SaaS) in AWS - Step-by-Step Execution

Process Flow - Cloud service models (IaaS, PaaS, SaaS)

User Needs Cloud Resources

↓

IaaS

↓

More Control

↓

User Installs

↓

and Runs OS

This flow shows how a user chooses between IaaS, PaaS, and SaaS based on how much control and management they want over cloud resources.

Execution Sample

AWS

User selects service model:
if model == 'IaaS':
  user manages OS and network
elif model == 'PaaS':
  user manages apps only
else:
  user uses ready apps

This code shows decision steps for what the user manages depending on the cloud service model chosen.

Process Table

Step	User Choice	Managed by User	Managed by Cloud	Resulting Control Level
1	IaaS	OS, Network, Storage, Apps	Hardware, Virtualization	High
2	PaaS	Apps	OS, Network, Storage, Runtime	Medium
3	SaaS	None	Everything (Apps + Infrastructure)	Low
4	Exit	N/A	N/A	User finished choosing service model

💡 User finishes choosing cloud service model and understands management responsibilities.

Status Tracker

Variable	Start	After IaaS	After PaaS	After SaaS
Managed by User	None	OS, Network, Storage, Apps	Apps	None
Managed by Cloud	All	Hardware, Virtualization	OS, Network, Storage, Runtime	Everything
Control Level	None	High	Medium	Low

Key Moments - 2 Insights

Why does the user manage more in IaaS than in SaaS?

Because in IaaS, the cloud only provides hardware and virtualization, so the user must manage OS and apps (see execution_table step 1 vs step 3). In SaaS, the cloud manages everything.

What does PaaS let the user focus on?

PaaS lets the user focus on building and managing apps only, while the cloud manages OS and infrastructure (see execution_table step 2).

Visual Quiz - 3 Questions

Look at the execution_table, what does the user manage in PaaS?

A OS and Network

B Everything

C Apps only

D Nothing

💡 Hint

Check the 'Managed by User' column at step 2 in execution_table.

At which step does the user have the highest control level?

A Step 1 (IaaS)

B Step 2 (PaaS)

C Step 3 (SaaS)

D Step 4 (Exit)

💡 Hint

Look at the 'Control Level' column in execution_table.

If the user wants to avoid managing OS, which model should they choose?

A PaaS

B SaaS

C IaaS

D None

💡 Hint

See which model leaves OS management to the cloud in execution_table.

Concept Snapshot

Cloud Service Models:
IaaS: User manages OS, network, storage; cloud manages hardware.
PaaS: User manages apps; cloud manages OS and infrastructure.
SaaS: Cloud manages everything; user just uses apps.
Choose based on control vs ease of use.

Full Transcript

This visual execution shows how cloud service models differ by what the user manages versus what the cloud manages. IaaS gives the user the most control but requires managing OS and apps. PaaS reduces user management to apps only. SaaS requires no management from the user, as the cloud handles everything. The execution table traces these differences step-by-step, showing management responsibilities and control levels. Key moments clarify common confusions about who manages what. The quiz tests understanding by referencing the execution table and variable tracker.