Cloud Computing and AWS

Welcome to your first SkillNest AWS lesson. Before learning services such as EC2 or S3, understand what cloud computing means and why organisations use it.

Learning objectives

By the end of this lesson, you should be able to:

• Explain cloud computing in simple words.
• Describe what Amazon Web Services (AWS) provides.
• Identify the main benefits and trade-offs of using the cloud.
• Explain the pay-as-you-go model and why cost awareness matters.

1. What is cloud computing?

Cloud computing means accessing computing resources over the internet when you need them, instead of buying and maintaining all the physical equipment yourself.

These resources can include:

• Compute: processing power to run applications.
• Storage: space for files, backups, images, and other data.
• Databases: systems for storing and querying structured or unstructured data.
• Networking: the connections and rules that let systems communicate.
• Security and monitoring: tools to control access and observe system health.

A simple example

Imagine you want to host a website. Traditionally, you might purchase a server, set it up, provide power and cooling, maintain it, and plan for future capacity. With cloud computing, you can provision a virtual server from a cloud provider and adjust its capacity as your needs change.

Cloud computing does not mean that physical computers disappear. The provider operates physical infrastructure, and you access resources through managed services and network connections.

2. What is AWS?

Amazon Web Services (AWS) is a cloud platform that offers services for computing, storage, databases, networking, identity, analytics, application delivery, and more.

Rather than one single product, AWS is a collection of services. You choose the services that fit your application and configure them for your requirements.

You will study each of these services in later lessons. For now, focus on the problem each service solves.

3. Why do organisations use cloud computing?

Speed and agility

Teams can provision resources in minutes rather than waiting to purchase and install physical hardware.

Elasticity and scalability

Capacity can be increased or decreased as demand changes. A well-designed system can scale to meet demand without permanently maintaining peak capacity.

Global reach

Cloud providers operate infrastructure in multiple geographic areas. This can help organisations serve users in different locations, subject to service availability and architecture choices.

Managed services

Some operational tasks are handled by the provider. The exact division of responsibility depends on the service, so customers still need to configure resources, protect data, and manage access appropriately.

Cost flexibility

Many services use usage-based pricing. This can reduce upfront hardware spending, but cloud resources are not automatically free or always cheaper. Costs depend on usage, architecture, data transfer, storage, and other factors.

4. Understand the pay-as-you-go model

Pay-as-you-go generally means that charges are based on how a service is used. Pricing differs by service and configuration, and some resources may continue to incur charges while idle.

Build these habits from your first lab:

1. Read the pricing information before creating a resource.
2. Use only the resources you need for the exercise.
3. Set up billing alerts or an appropriate budget where available.
4. Stop or delete resources when the lab is finished.
5. Review storage, snapshots, and other resources that may remain after a lab.

For current pricing and free-tier eligibility, always check the official AWS website. Terms and offers can change.

5. Shared responsibility: a first look

Cloud security is shared between AWS and the customer. AWS is responsible for security of the cloud, such as the underlying infrastructure. Customers are responsible for security in the cloud, including the configuration and use of services, access permissions, and data protection, depending on the service.

For example, choosing AWS does not automatically make every file public or private in the way you intend. You must configure permissions correctly and review who can access your resources.

Remember these key terms

• Cloud computing: accessing computing resources over the internet on demand.
• Cloud provider: a company that offers cloud infrastructure and services.
• Scalability: the ability to adjust capacity to meet changing demand.
• Pay-as-you-go: a pricing approach where charges depend on usage and service-specific rules.
• Shared responsibility: security duties are divided between the provider and the customer.

Quick knowledge check

Question: What is one key benefit of cloud computing?

A. You must buy every server before launching an application. B. You can provision resources when needed and adjust capacity. C. Every cloud service is always free.

Correct answer: B. Cloud resources can be provisioned on demand and adjusted as requirements change. Remember to monitor usage and understand pricing.

Try explaining it in your own words

Before moving on, try answering these questions without looking at the lesson:

1. What is cloud computing?
2. What is AWS?
3. Name two benefits and one cost consideration.
4. Why is cloud security a shared responsibility?

If you can explain these simply, you are ready for Topic 02: AWS global infrastructure — Regions and Availability Zones.

Official resources

• What is cloud computing? — AWS
• Getting started with AWS
• AWS pricing