• Software as a Service (SaaS): SaaS architecture providers deliver and maintain applications and software to organizations over the Internet, thereby eliminating the need for end users to deploy the software locally. SaaS applications are typically accessed via a web interface available from a broad variety of devices and OSes. 
  
• Platform as a Service (PaaS): In this cloud model, the service provider offers a computing platform and solution stack, often including middleware, as a service. Organizations can build upon that platform to create an application or service. The cloud service provider delivers the networks, servers and storage required to host an application while the end user oversees software deployment and configuration settings. 
• Infrastructure as a Service (IaaS):In this, cloud at its simplest form, a third-party provider eliminates the need for organizations to purchase servers, networks or storage devices by providing the necessary infrastructure. In turn, organizations manage their software and applications, and only pay for the capacity they need at any given time.  

Organizations have many reasons for adoption of a cloud architecture. Chief among them is to:

• Accelerate the delivery of new apps
  
• Take advantage of cloud-native architecture such as Kubernetes to modernize applications and accelerate digital transformation.
•  Ensure compliance with the latest regulations 
• Deliver greater transparency into resources to cut costs and prevent data breaches 
• Enable faster provisioning of resources  
• Utilize hybrid cloud architecture to support real-time scalability for applications as business needs change 
• Meet service targets consistently
•  Leverage cloud reference architecture to gain insight into IT spending patterns and cloud utilization 

Although no two clouds are alike, there are a number of common cloud architecture models. These include public, private, hybrid and multi-cloud architectures. Here is how they compare:

• Public cloud architecture: In a public cloud architecture, computing resources are owned and operated by a cloud services provider. These resources are shared and redistributed across multiple tenants via the Internet. Advantages of the public cloud include reduced operating costs, easy scalability and little to no maintenance. 
  
• Private cloud architecture: Private cloud refers to a cloud that is owned and managed privately, usually in a company’s own on-premises data center. However, private cloud can also span to include multiple server locations or leased space in geographically scattered colocation facilities. Although typically more expensive than public cloud solutions, a private cloud architecture is more customizable and can offer stringent data security and compliance options. 
• Hybrid cloud architecture: A hybrid cloud environment combines the operating efficiencies of the public cloud and data security capabilities of the private cloud. By utilizing both public and private cloud architectures, hybrid clouds help consolidate IT resources while enabling organizations to migrate workloads between environments depending on their IT and data security requirements.  
• Multi-cloud architecture: A multi-cloud architecture is one that uses multiple public cloud services. The advantages of a multi-cloud environment include greater flexibility to choose and deploy the cloud services that are most likely to satisfy varying organizational requirements. Another upside is reduced reliance on any single cloud services vendor for greater cost savings and a lower likelihood of vendor lock-in.  Additionally, multi-cloud architecture may be required to support microservices-based containerized applications, where services exist on multiple clouds. 

The fundamental components of cloud architecture include: 

• Virtualization: Clouds are built upon virtualization of servers, storage, and networks. Virtualized resources are a software-based, or virtual, representation of a physical resource such as servers or storage. This abstraction layer enables multiple applications to utilize the same physical resources, thereby increasing the efficiency of servers, storage, and networking throughout the enterprise. 
• Infrastructure: Yes, there are real servers. Cloud infrastructure includes all the components of traditional data centers including servers, persistent storage and networking gear including routers and switches. 
• Middleware: As in traditional data centers, these software components such as databases and communications applications enable networked computers, applications and software to communicate with each other.
• Management: These tools enable continuous monitoring of a cloud environment’s performance and capacity. IT teams can track usage, deploy new apps, integrate data and ensure disaster recovery, all from a single console. 
• Automation software: The delivery of critical IT services through automation and pre-defined policies can significantly ease IT workloads, streamline application delivery, and reduce costs. In a cloud architecture, automation is used to easily scale up system resources to accommodate a spike in demand for compute power, deploy applications to meet fluctuating market demands, or ensure governance across a cloud environment.  

VMware provides a unified approach to building, running, and managing traditional and modern applications on any cloud. A single platform functions across all applications and multiple cloud environments, so organizations can migrate and run applications seamlessly. 

VMware allows enterprises to create application modernization and multi-cloud strategies that support cloud operations across a multi-cloud landscape, including both hybrid cloud and public cloud native architectures. Enterprises can architect the multi-cloud environment that best match their applications, with the flexibility to build, deploy, and manage from the data center to the cloud to the edge. 

VMware allows enterprises to create application modernization and multi-cloud strategies that support cloud operations across a multi-cloud landscape, including both hybrid cloud and public cloud native architectures. Enterprises can architect the multi-cloud environment that best match their applications, with the flexibility to build, deploy, and manage from the data center to the cloud to the edge. 

The result is real-time visibility into cloud security and compliance postures thanks to continuous monitoring of cloud resource configuration and benchmarks to meet different industry standards, cloud computing security architectures, and regulatory compliance requirements. 

A well-architected framework for the cloud is more than simply a technology necessity; it is a vehicle for lower operating costs, high-performing applications and satisfied end users. By following cloud architecture principles and best practices, organizations can ensure they reap real business value from their cloud investments and future-proof their IT environment. 

• Up-front planning: Ensure there is an understanding of capacity needs when designing a cloud architecture. As organizations begin to build out architecture, continuously test performance to avoid experiencing unexpected glitches in production. 
  
• Security first: Protect clouds from hackers and unauthorized users by safeguarding all layers within a cloud infrastructure with data encryption, patch management and rigid policies. Consider zero-trust security models for the highest levels of security across the hybrid, multi-cloud enterprise. 
• Ensure disaster recovery: Automate recovery processes to avoid costly downtime and ensure a speedy recovery from service disruptions. Monitoring capacity and using a redundant network can also ensure a highly available architecture.
• Maximize performance: Leverage and manage the right compute resources by continuously monitoring business demands and technology needs. 
• Cut costs: Take advantage of automated processes, managed service providers and utilization tracking to eliminate unnecessary cloud computing expenses.