Cloud computing

Cloud computing is a way to use the internet to store and process information instead of using a computer's own hard drive. Imagine having access to all your files, programs, and apps from any device with an internet connection. This idea is often called "the cloud" because it’s like magic – your data seems to float in the air, ready whenever you need it.

The International Organization for Standardization describes it as a system that lets people easily get and manage resources over the internet. These resources can be servers, storage space, databases, software, and more. One big advantage is that you don’t have to buy and maintain your own expensive computer equipment. Instead, you can rent what you need, when you need it, and only pay for what you use.

Cloud computing has changed how people and businesses work. Schools, hospitals, and even video game companies use the cloud to save money, share information quickly, and make things run faster. It helps everyone from individual students doing homework to large companies launching new products. Because of this, cloud computing has become an important part of our modern, digital world.

Characteristics

In 2011, the National Institute of Standards and Technology named five important parts of cloud systems. These parts are:

Users can easily get computing resources, like server time and storage, whenever they need them.
Users can access these resources over the internet from devices like mobile phones, tablets, laptops, and workstations.
Resources are shared to serve many users at once.

Cloud systems can also change resources quickly based on demand, making it seem like there is always enough available. Finally, these systems keep track of how resources are used. This helps both the provider and the user understand and manage the services. By 2023, the International Organization for Standardization updated this list.

Main article: Cloud computing

History

Main article: History of cloud computing

The idea of cloud computing began in the 1960s when people started sharing computer time over long distances. At that time, people sent jobs to operators who used large computers called mainframes to process them.

The term “the cloud” for online services first appeared in 1994. In the 2000s, companies like Amazon Web Services began offering tools for building apps online. Later, other big names like Microsoft Azure and IBM SmartCloud joined in, helping cloud computing become more popular.

Value proposition

Cloud computing helps businesses and individuals save time and money. It gives people tools and resources they can use online without needing to set up complicated equipment. This lets people focus on their work instead of technical problems.

Even though cloud computing can save money, it can also lead to wasted resources or surprise costs if not managed well. Many cloud services have tools to help track spending. The cloud also helps teams work together from anywhere by letting them access files and programs on the internet.

Cloud providers and users share responsibilities. Providers make sure the systems are secure and running well, while users need to protect their own data and manage who can access it. Different types of cloud services — like Infrastructure as a Service, Platform as a Service, and Software as a Service — change how much control users have over their data and settings.

Main article: shared responsibility model

Adoption and suitability

Choosing between cloud computing and on-premises infrastructure depends on several factors like scalability, cost, speed needs, rules, and customization.

Businesses with changing needs, limited startup money, or a need to grow quickly often find cloud computing helpful. Startups, software companies, and online shops usually like the "pay as you go" way of cloud services. They also like how the cloud helps them reach people all over the world, support remote workers, recover from problems, and use smart tools like artificial intelligence.

However, some companies, like those in defense or government, or those with very strict rules or very fast needs, might prefer to keep their systems on their own premises. Very large tech companies also often build their own data centers for better control and efficiency, though they still use cloud services for some tasks.

Many companies now use a mix of both cloud and on-premises systems, which gives them the best parts of both ways.

Challenges and limitations

Cloud suppliers security and privacy agreements must be aligned to the demand(s) requirements and regulations.

Cloud computing has some challenges compared to keeping data and programs on your own computers. One big challenge is keeping data safe and private. When you use cloud services, you trust another company to look after your important information. Sometimes, these companies might not have strong enough safety measures.

Another challenge is that you might not always know exactly how your data is being handled. This can make it hard to change things to fit your needs. Moving your data and programs to the cloud can also be tricky and take a lot of time and money. Sometimes, this can cause problems like slow speeds.

Service models

Deployment models

A cloud deployment model shows how cloud computing is organized based on who controls and shares the resources. There are several main ways to set up a cloud.

Private clouds are used by just one organization. They can be run by that organization itself or by another company, and they can be hosted either inside or outside the organization’s buildings. Private clouds need careful planning.

Public clouds are services offered over the regular Internet, either for a fee or for free. While they work similarly to private clouds, public clouds can have more security concerns because many different people might use the same services.

Hybrid clouds mix public and private clouds. This lets an organization keep sensitive data private while using public cloud services for other tasks. For example, a company might keep important customer information on its own private system but use a public cloud for data analysis. Hybrid clouds can also help when an organization needs more power suddenly — it can use the public cloud to handle extra work and then go back to its private system afterward.

Community clouds are shared among several organizations that have similar needs, like specific security rules. This saves money compared to a public cloud.

Multi cloud means using services from two or more cloud providers. This helps organizations get the best features from each provider.

Market

Global spending on cloud computing services has grown a lot. In 2012, it was $706 billion, and it may grow even more. Many big companies can use cloud services in smart ways.

In 2012, the European Commission talked about some challenges for cloud computing. They suggested several actions to help create a better market for these services.

Main article: Cloud computing

Cloud Computing Vendors

As of 2025, the three biggest cloud computing providers are Amazon Web Services (AWS), Microsoft Azure, and Google Cloud. These companies are popular because they have lots of tools and services.

Some smaller cloud providers also exist. They can help save money and follow local rules, especially in places like the European Union. These smaller providers are often used with the bigger ones to get better performance.

Similar concepts

Cloud computing helps people use technology without needing to understand all the details. It saves money and lets users focus on their tasks instead of dealing with complicated IT issues. The main technology that makes cloud computing work is virtualization, which lets one physical device act like many virtual devices. This helps use resources better and speeds up tasks.

Cloud computing shares ideas with several other concepts. It is like the client–server model, where some devices provide services and others request them. It also relates to older computer bureau services, modern grid computing, nearby fog computing, useful utility computing, and peer-to-peer networks where everyone shares resources equally. It can also use a cloud sandbox to test programs safely.