The cloud is access to computing resources —servers, storage, databases, and software— over the internet, instead of having them physically in the office. You pay for what you use and capacity grows or shrinks with demand. It is the foundation on which most modern digital applications and services run today.

What problem does the cloud solve?

For decades, standing up a digital service meant buying servers, hosting them in a conditioned room, maintaining them, and replacing them every so often. That required a large upfront investment and forced companies to guess how much capacity they would need: if there was too much, money was wasted; if there was too little, the service went down during peak demand.

The cloud solves that dilemma. Instead of buying capacity in advance, the company consumes exactly what it needs at each moment from a provider’s data centers, and pays only for that consumption. Capacity adjusts elastically: it scales up during peaks and down when demand drops.

What is cloud computing?

Cloud computing is the model that delivers those resources on demand. A provider like AWS operates the physical infrastructure —the data centers, the networks, the security— and makes it available as services that the company consumes over the internet.

This changes the logic of spending: the fixed investment in hardware (CapEx) becomes a variable expense aligned with actual usage (OpEx). And it changes speed: launching a new environment goes from weeks of purchasing and installation to minutes of configuration.

The three service models: IaaS, PaaS, and SaaS

Not all cloud is the same. There are three levels depending on how much the provider manages and how much the company does:

  • IaaS (Infrastructure as a Service): the provider delivers the basic building blocks —compute, storage, and network— and the company builds on top of them. It is the level of greatest control and flexibility.
  • PaaS (Platform as a Service): in addition to infrastructure, the provider offers a ready-to-use platform for building and deploying applications without managing the underlying servers. The team focuses on the code.
  • SaaS (Software as a Service): the provider delivers complete, ready-to-use applications through the browser, with the company administering none of the infrastructure.

The rule is simple: the higher the level, the less technical administration on the customer’s side and the more focus on the business. Most organizations combine all three depending on each need.

Cloud benefits for the business

  • Lower upfront investment: the advance purchase of hardware is eliminated; spending becomes variable and proportional to usage.
  • Elastic scalability: capacity grows during peaks and shrinks during troughs, without over-provisioning.
  • Availability and resilience: providers operate across multiple zones, which makes it easier to design services that stay up when failures occur.
  • Managed security: the infrastructure relies on the provider’s constant controls, certifications, and updates.
  • Speed to innovate: launching and testing new ideas takes minutes, which shortens the time between idea and result.

Types of cloud: public, private, and hybrid

Depending on where the resources reside, we talk about public cloud (a provider’s shared infrastructure), private cloud (dedicated to a single organization), and hybrid cloud (a combination of both that keeps certain workloads on premises and moves others to the public cloud). The choice depends on goals, regulation, and each company’s starting point.

How to start in the cloud with a clear plan

Adopting the cloud is not turning on servers at random: it is a business decision worth structuring. The recommended approach is to start with an assessment —what applications exist, what goals there are, and which workloads to move first— and then design a realistic roadmap.

At Caleidos we guide that journey as part of our cloud strategy practice on AWS: we define the architecture, prioritize workloads, and, when applicable, run the migration in phases. For modern, lightweight architectures, many organizations also move toward serverless models. Our case studies document results in production.

Frequently asked questions

What is the cloud in simple terms? It is access to servers, storage, databases, and software over the internet, paying only for what you use.

What is the difference between IaaS, PaaS, and SaaS? They are three service levels: IaaS delivers infrastructure, PaaS a development platform, and SaaS ready-to-use applications; the higher the level, the less administration on the customer’s side.

How do you get started with the cloud? With an assessment of applications and goals, a cloud strategy, and, if applicable, a phased migration plan.

Want to move your operation to the cloud with a clear plan?

Let’s talk about your current situation and we will give you a concrete recommendation on how to take your first steps on AWS.