What Is the Difference Between Cloud And On Premises?

The primary differences between cloud and on premises computing models are the location of your physical IT infrastructure and who manages that infrastructure. Your organization owns and maintains on premises infrastructure on site in your data center. You, or your delegates, have full control over hardware, security, and operations.

In a cloud computing model, you access various services, such as public cloud services for storage, computing power, or databases, from a cloud provider such as Amazon Web Services (AWS). The cloud provider manages the physical infrastructure.

Although on premises systems offer direct control and can be preferred in some use cases, they often need significant upfront investment and ongoing maintenance. In contrast, cloud environments offer more flexibility and scalability, and can reduce the long-term resource overhead of managing physical IT infrastructure.

Cloud and on premises computing models offer different capabilities and have different requirements.

Cloud computing

In cloud computing, a provider delivers IT resources over the internet as services. Instead of buying and maintaining servers or entire data centers, you access computing power, data storage, databases, and applications on demand.

Service delivery by cloud providers is through one of three service models:

• Infrastructure as a Service (IaaS): A cloud service provider offers virtualized computing resources over the internet in this model. For example, these resources can include virtual machines, networking resources, and storage. You are responsible for running and managing the operating systems, applications, and other resources you wish to use on that infrastructure.
• Platform as a Service (PaaS): The provider offers a development cloud solution for software engineers to build, test, and deploy applications. The provider manages the underlying infrastructure, operating system, and runtime. You are responsible for the code, data, and application configurations.
• Software as a Service (SaaS): The provider delivers ready-to-use cloud software applications, such as email, collaboration tools, or customer relationship management (CRM) systems. The provider manages infrastructure, feature updates, and cloud security patching. You are responsible only for your data, access management, and application configurations.

You can typically scale the cloud computing resources you purchase up or down in minutes, depending on your use case. Costs are typically pay-per-use or subscription-based, and the provider handles infrastructure maintenance.

On premises architecture

In this model, you run your own IT systems on hardware physically located within your organization’s data center on-site. You are responsible for purchasing, installing, and managing all components.

This model can provide more control over system and data security and performance, however, it typically requires more upfront investment and ongoing maintenance. Therefore, organizations need to employ IT staff for management.

Unlike cloud-based systems, scaling on premises systems can require more time and planning. You will also often need to purchase and configure new systems.

On premises servers are often preferred for highly regulated environments, when you work with sensitive data, or for latency-sensitive applications.

Hybrid cloud computing

Today, many organizations use a mix of both cloud and on premises models depending on the use case. This is known as hybrid cloud. Organizations may choose to keep critical or specialized systems on premises while adopting cloud solutions to support international business, remote work, and scalable or rapid growth projects. Among other factors, business needs, budget, compliance requirements, and long-term technology strategy help define the best infrastructure to use on a case-by-case basis. Hybrid cloud infrastructure can also be an intermediate step before starting full cloud operations.

Understanding the key differences between cloud and on premises systems can help you make an informed decision about when to use which model.

Ownership

With on premises infrastructure, your organization owns the physical hardware and must maintain it within your own data center. You are responsible for every aspect of its lifecycle. In contrast, cloud computing uses large-scale, shared resources owned and maintained by a provider, such as AWS, and you don’t own the hardware. Instead, you pay periodically for various cloud computing services offered by a third-party provider. The exact shared responsibility model in cloud computing depends on the cloud provider.

Degree of configuration

On premises environments offer full control over system configurations, which is most useful when you need to meet specific technical or compliance standards. Cloud computing environments can also support extensive configuration to meet compliance standards, but they operate within the boundaries of the provider’s architecture.

Management overhead

Running on premises systems requires ongoing management. Owners are responsible for the full system lifecycle, from installation, patching, monitoring, and troubleshooting to decommissioning. With cloud computing resources, many of these tasks shift to the cloud service provider, especially concerning physical infrastructure. You can manage services at scale through purpose-built cloud tools, which reduces the need for large internal IT teams focused on infrastructure upkeep.

Maintenance requirements

Maintenance of on premises systems can require planning downtime or scheduling to implement replacement parts or license orders. Cloud service providers are responsible for maintaining the infrastructure of cloud computing environments. Due to their larger scale, providers typically perform rolling updates, taking one section of infrastructure down at a time, with no perceptible impact to customers. Depending on your choice of cloud services, you might be responsible for tasks such as updating and patching operating systems on your cloud instances.

Cost model

On premises infrastructure requires significant upfront spending on hardware, software licenses, and facilities. Ongoing expenses can include power for physical servers, cooling, and staffing. Cloud computing environments use a pay-as-you-go model, where you only pay for the resources you use. In some organizations, that means you can transition from making capital expenditures on IT to operational expenses, which can result in cost savings.

Scalability

Scaling up on premises systems requires planning, investment, procurement, and installation. This process typically takes a long time. On premises systems cannot scale down in hardware; the infrastructure is idle or switched off unless you decommission the system. In cloud environments, scaling resources up or down can occur in near real-time, as capacity is available on demand.

Certain workloads are better suited to cloud environments and others to on premises environments. That determination depends on factors such as performance demands, budget, latency, data sensitivity, and scalability requirements.

Cloud applications

Cloud applications are often dynamic, user-facing services that benefit from rapid scaling capability and global availability. Examples include:

• Web and mobile apps
• ecommerce systems
• Customer service portals
• Collaboration software

Development and testing environments are also increasingly common in cloud environments, where teams can quickly spin up resources and automate deployments. SaaS applications such as email, HR systems, and productivity suites, which need to be designed for access at any time from anywhere, are also well-suited to running on cloud infrastructure.

On premises applications

On premises software applications might have a requirement to run on legacy systems or perform highly regulated workloads, with strict latency, compliance, or security requirements. Typical examples include:

• Banking systems
• Medical imaging platforms
• Industrial control systems
• Customized, internal ERP or CRM solutions

Although these workloads can run in the cloud, it is often far more complex to configure.

Hybrid approaches

Many organizations take a hybrid approach and use a mix of cloud and on premises services. Using this approach, you can choose the best system for each application and help balance competing business interests, such as control and agility.

Use the cloud when:

You need speed, scalability, and flexibility. Cloud services are a good fit for organizations that are scaling quickly, developing or launching new applications, or have a distributed workforce. Cloud infrastructure is well-suited for hosting web and mobile apps, development environments, and data analytics services. The billing model helps you scale operations more quickly and reduce IT management overhead.

Use on premises when:

You require full control over your IT infrastructure, have strict data residency requirements, or operate in a highly regulated industry such as government, defense, or healthcare.

On premises solutions can also be a better choice if your applications must run on legacy infrastructure that can’t easily migrate to the cloud. If directly managing physical security and minimizing third-party dependencies is a top priority, on premises can be the better choice.

	Cloud	On Premises
Ownership	Infrastructure is owned and maintained by the cloud provider.	Your organization owns and operates the physical hardware and infrastructure in your own data center.
Degree of configuration	Offers extensive configuration options, including compliance controls and infrastructure settings.	Provides full control over system and hardware settings, enabling deep customization for specific needs or compliance requirements.
Management overhead	Minimal. Most management tasks are handled by the provider, reducing the need for large internal IT teams.	High. Typically requires dedicated staff to manage servers, networks, security measures, and day-to-day operations.
Maintenance requirements	The provider performs maintenance without system disruptions to you.	You are responsible for all maintenance, including upgrades, troubleshooting, and decommissioning equipment.
Cost model	Pay-as-you-go model where you only pay for the resources you use. Allows IT services to be operational rather than capital expenses.	High upfront investment in hardware, software, and facility setup, plus ongoing operational costs.
Scalability	Can scale up or down in minutes to hours based on demand and use case.	Limited by physical capacity. Scaling requires time, planning, and additional hardware purchases.

AWS offers a full range of cloud services, infrastructure, and support to help you meet all your cloud computing requirements. AWS plugs into your on premise infrastructure with a range of connectivity options designed for modern cloud interaction.

Here are just a few of our most popular cloud service offerings:

• Amazon EC2 offers secure and resizable compute capacity for virtually any workload, with over 750 instances and a choice of the latest processor, storage, networking, operating system, and purchase model to help you best match the needs of your workload.
• AWS Lambda allows you to run code without thinking about servers or clusters, with its serverless compute options.
• Amazon S3 is object storage built to retrieve any amount of data from anywhere, offering industry-leading scalability, data availability, security, and performance.
• Amazon SageMaker AI allows you to build, train, and deploy ML models—including foundation models—for any use case with fully managed infrastructure, tools, and workflows.

Get started with cloud services on AWS by creating a free account today.