
Cloud Computing
Applied IT (Year 11) - Managing Data (U2)
Jeckmen Wu
What is Cloud Computing?
Cloud computing uses the internet to deliver on-demand access to computing resources (e.g. storage, web mail, office software, content streaming, applications) to client devices. This enables users to carry out common computer activities over the web by using resources and services hosted on a global network of remote servers and databases instead of relying on their own infrastructure (i.e. their local computer/server).Â
There are 3 main cloud computing service models (i.e. types of services offered by a cloud provider):Â
Infrastructure as a Service (IaaS) – also known as virtualisation, the provider delivers virtualised computing resources (i.e. servers, storage, processing units) to the users (e.g. Microsoft Azure, Amazon Web Service, Google Cloud Platform).
Platform as a Service (PaaS) – provides a platform for the user to develop and manage their own application (e.g. Google App Engine, Wix, Squarespace).
Software as a Service (SaaS) – offers users access to the complete application over the internet as everything is hosted and managed by the provider (e.g. Gmail, Microsoft 365 Online, Prezi, Dropbox).

Image: IaaS vs. PaaS vs. SaaS, Image by Artifakt (https://www.artifakt.com/blog/paas/paas-vs-iaas-vs-saas-differences-pros-and-cons/)Â Â
Advantages
Accessibility – users can conveniently access their data from any internet-connected device, regardless of time or location, as their data is stored online in the cloud rather than locally on a specific device.
Cost Savings – cloud computing services can offer cost-saving benefits to users by renting out their vast network infrastructures to users through subscription plans. These plans enable individuals/businesses to pay only for the computing resources they require at any given time, reducing the upfront costs of purchasing and maintaining their own infrastructure. The ability for users to easily upgrade or downgrade subscription plans as their needs change provides flexibility and scalability. This is particularly useful for businesses as they can avoid the need to constantly upgrade their infrastructure (e.g. servers, storage space) as they grow or being burdened with unused resources during periods of low activity. Â
Disaster Recovery – disaster recovery as a service (DRaaS) replicates a business’s servers in a third-party offsite facility so that in the event of a disaster (e.g. natural disaster, power outage, equipment failure, cyberattack), the computer processing can be moved from the damaged on-premises servers to the cloud infrastructure. This is often combined with backup as a service (BaaS), which enables businesses to back up or archive their data with the cloud provider. The goal is to ensure business continuity until the physical on-site servers have been recovered/replaced. By leveraging DRaaS & BaaS, businesses can minimise downtime, reduce data loss, and protect critical applications.Â
DisadvantagesÂ
Security/Privacy – storing data in the cloud can pose security risks (e.g. data breaches, cyberattacks, unauthorised access) as you are surrendering control of the data to the cloud provider, who may not always have adequate security measures in place to safeguard it.
Dependent on Internet Connection – since the data is stored offsite on a network of servers, accessibility of data in the cloud is dependent on a fast & reliable internet connection, which can be problematic in areas with poor connectivity.
Risk of Downtime – users are also dependent on the reliability of the provider’s infrastructure and the frequency of scheduled maintenance downtime or unforeseen outages.