When we say "the cloud," there are actually several clouds competing with each other. The three largest are AWS, Azure, and Google Cloud. Knowing them helps you understand the market and make good professional decisions. Let's look at them without marketing, with real data and differences.

Providers with data centers all over the world and a huge catalog of services are called hyperscalers. There are three dominant ones:

• Who: Amazon's cloud division.
• Launch: 2006. It was the first to offer modern public cloud.
• Position: market leader, the most mature, and with the broadest service catalog.
• Fun fact: it was born because Amazon needed to manage its own infrastructure for the holidays and decided to rent out that surplus capacity to third parties.

• Who: Microsoft's cloud.
• Launch: 2010.
• Strength: integration with the Microsoft world (Windows Server, Active Directory, Office 365, .NET). Very present in large companies that were already using Microsoft software.

• Who: Google's cloud.
• Launch: 2011 (as a general platform).
• Strength: data, analytics, machine learning, and Kubernetes (which Google invented). Very popular with data and engineering teams.

The exact figures change every quarter, but the order has remained stable for years:

Don't memorize the exact numbers, they change. The important thing is the pattern: AWS leads, Azure follows closely, and GCP is a solid third. Together they dominate most of the market.

Although all three do "the same" at a high level (servers, storage, databases…), they have distinct personalities:

A detail that confuses beginners: each provider calls the same thing something different. For example, a virtual server is called:

• EC2 in AWS.
• Virtual Machines in Azure.
• Compute Engine in GCP.

The concept is identical; only the commercial name changes. We'll see this in subchapter 2.3.

Not necessarily. There are strategies:

• Mono-cloud: use a single provider. Simpler, easier to master. This is the most common and recommended when starting out.
• Multi-cloud: use several providers at once. Offers flexibility and avoids depending on just one, but multiplies complexity. Usually done by large organizations with specific reasons.

Here comes the concept of vendor lock-in: the more you use proprietary and exclusive services from a provider, the harder it will be to switch later. It's not inherently good or bad; it's just something to keep in mind. Tools like Terraform (which we'll see in Part III) help you avoid getting too tied down, because they let you manage multiple providers with a common language.

• The three major cloud providers ("hyperscalers") are AWS, Azure, and Google Cloud.
• AWS leads, Azure is second (strong in the Microsoft world), and GCP is third (strong in data and AI).
• They do the same at a high level, but each calls their services differently and has its own personality.
• You can use one (mono-cloud, recommended when starting) or several (multi-cloud, more complex).
• Vendor lock-in is the dependency you create by using exclusive services from a provider.

In the next subchapter, we'll explain why in this book we'll learn AWS first.