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 identified five key features of cloud systems. These include the ability for users to easily get computing resources like server time and storage whenever they need it, access to these resources over the internet from devices like mobile phones, tablets, laptops, and workstations, and the pooling of resources to serve many users at once.

Cloud systems can also quickly adjust resources up or down based on demand, making it seem like there is an endless supply available. Finally, these systems track how resources are used, which helps both the provider and the user understand and manage the services being used. By 2023, the International Organization for Standardization had updated and improved this list.

Main article: Cloud computing

History

Main article: History of cloud computing

The idea of cloud computing started in the 1960s when people began sharing computer time with others over long distances. Back then, people sent jobs to operators who used big 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, making cloud computing more popular.

Value proposition

Cloud computing helps businesses and individuals save time and money. It provides ready-to-use tools and resources that users can access online, so they don’t need to set up their own complex equipment. This way, people can focus on their main work instead of dealing with technical details.

Although cloud computing can cut costs, it also comes with challenges like wasted resources or unexpected expenses if not managed well. Luckily, many cloud services include tools to help track spending. The cloud also makes it easier for teams to work together from anywhere in the world by letting them access files and programs over the internet.

Cloud providers share responsibilities with their users. The providers take care of the basic security and upkeep of the systems, while users need to protect their own data and manage access permissions. 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 traditional ways of 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, which could lead to problems if someone tries to see or steal your data.

Another challenge is that you might not always know exactly how your data is being handled or what the company is doing with it. 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, especially if the different cloud services don’t work well together. Sometimes, this can cause problems like slow speeds or even loss of data if not done carefully.

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 a lot of planning and can involve many security questions.

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 “burst” into 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 but not as much as a private 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 significantly, reaching $706 billion and is expected to continue growing. By 2025, it may reach $1.3 trillion. Many large companies can benefit from using cloud services in smart ways.

In 2012, the European Commission noted some challenges for cloud computing, such as different rules in various parts of Europe and concerns about data ownership. 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 largest cloud computing providers are Amazon Web Services (AWS), Microsoft Azure, and Google Cloud. These companies are very popular because they have lots of infrastructure and offer many different services.

Some organizations also use smaller cloud providers that offer special services. These smaller providers can help save money, make costs easier to understand, and follow local rules, especially in places like the European Union. They are often used along with the big providers to get the best performance and save money, but they usually don’t replace the big companies.

Similar concepts

Cloud computing helps people use technology without needing to understand all the details. It saves money and lets users focus on what they need to do 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.