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Cloud Computing

Using computing services over the internet: SaaS, PaaS and IaaS; public, private and hybrid clouds; benefits and drawbacks.

What Is the Cloud?

The U.S. National Institute of Standards and Technology (NIST) describes cloud computing with five characteristics: on-demand self-service, broad network access (from any device), resource pooling (many customers share big data centres), rapid elasticity (grow or shrink quickly) and measured service (pay for what you use).

Public cloud — shared data centres run by a provider (Microsoft, Amazon, Google). Cheapest and easiest. Private cloud — used by one organisation only, for more control (banks, government). Hybrid cloud — a mix: sensitive data kept private, other work in the public cloud.

Cloud for a small business

$Benefits$	$Drawbacks$
$No expensive server to buy or maintain$	$Monthly fees continue for as long as you use it$
$Access files from anywhere, on any device$	$Needs a reliable internet connection$
$Automatic updates and backups by the provider$	$Data is stored by another company — check privacy and where it is kept$
$Easy to grow or shrink$	$Moving to another provider can be difficult ("lock-in")$

Practice

During the tourist season, the tea room's online booking system gets ten times more visitors. Which cloud characteristic helps most?

What Is the Cloud?

The U.S. National Institute of Standards and Technology (NIST) describes cloud computing with five characteristics: on-demand self-service, broad network access (from any device), resource pooling (many customers share big data centres), rapid elasticity (grow or shrink quickly) and measured service (pay for what you use).

Service Models

Benefits and Drawbacks

Cloud for a small business

$Benefits$	$Drawbacks$
$No expensive server to buy or maintain$	$Monthly fees continue for as long as you use it$
$Access files from anywhere, on any device$	$Needs a reliable internet connection$
$Automatic updates and backups by the provider$	$Data is stored by another company — check privacy and where it is kept$
$Easy to grow or shrink$	$Moving to another provider can be difficult ("lock-in")$

Practice

During the tourist season, the tea room's online booking system gets ten times more visitors. Which cloud characteristic helps most?