What is cloud infrastructure?

Cloud service providers (CSPs), including Amazon Web Services (AWS), Google Cloud, Microsoft Azure and IBM Cloud—manage these resources in global data centers, providing on-demand access and allowing users to scale and shrink resources as needed. This centralization offers businesses flexibility, scalability and cost-efficiency compared to investing in on-premises hardware.

A fundamental characteristic of cloud computing is the virtualization of IT infrastructure, including servers, networking components and storage. Virtualization connects physical servers maintained by a cloud service provider (CSP) at numerous locations, then divides and abstracts resources to make them accessible to end-users wherever there is an internet connection. 

At the heart of virtualization is hypervisor software. This technology creates an abstraction layer that enables multiple virtual machines (VMs) with their own operating systems (OS) to run on one server. The hypervisor pools and allocates computing resources as needed by the VM. VMware holds the largest market share in the virtualization platform marketplace, with approximately 42.77%^.1

Another core technology associated with modern cloud infrastructure is microservices (or microservices architecture), the cloud-native architectural approach in which a single application comprises many loosely coupled and independently deployable smaller components or services.

Cloud-native applications are deployed in containers— executable units of software that package application code along with its libraries and dependencies. Container orchestration tools, such as the open-source solution Kubernetes, then schedule the automated deployment, management and scaling of those applications across all cloud environments.

Cloud technology infrastructure consists of hardware and software components that work together to deliver the scalability, flexibility and accessibility required for cloud computing.

The following key hardware and software components comprise a cloud infrastructure environment:

• Servers

• Storage

• Network

• Software

A  server in the cloud is a physical or virtual infrastructure that delivers applications, processes information and provides data storage. These powerful resources are optimized for specific workloads, including artificial intelligence (AI), machine learning (ML), big data and high-performance computing (HPC).

Depending on an organization’s needs, a cloud server can be physical (bare metal), virtual, or a mix of the two. For instance, bare metal servers are generally best for data-intensive workloads, while virtual servers are better suited for highly variable workloads.

Cloud storage relies on servers to save data in CSP-owned data centers. The majority of these servers are VMs hosted on a physical server. Cloud storage provide elasticity, which allows users to scale capacity as data volumes increase or dial down capacity, if necessary. 

Users connect to a storage cloud through the internet or a dedicated private connection using a web portal, website, or mobile app that communicates through an API. The connecting server then forwards data to a pool of servers in one or more data centers.

The main types of storage services in the cloud include object storage for unstructured data, file storage for shared files and block storage for I/O-intensive workloads.  

The network is a critical component of cloud infrastructure because it enables communication and data exchange between various cloud resources. Networking hardware includes physical devices like switches, routers and other equipment.

In cloud environments, networking equipment is often virtualized over physical resources. For instance, virtual switches manage traffic between virtual machines, ensuring seamless communication. Additionally, virtualized load balancers distribute incoming traffic across servers to improve performance and reliability, while virtual firewalls control network traffic to protect cloud resources.

Cloud infrastructure uses wide area networks (WANs) to connect geographically dispersed resources and local area networks (LANs) or virtual local networks (VLANs) within the cloud environment to create and manage virtual networks. Today, many cloud infrastructure environments also rely on software defined networking (SDN), which enables centralized, software-controlled management of network resources.

Cloud management software tools provide a central hub for monitoring and managing cloud resources and optimizing costs. Tools like a dashboard or platform create a single pane of glass (SPOG) that provides visibility and unifies information. This capability helps users make more informed decisions regarding performance, inventory and logging.

Software automation tools also provide cloud security and compliance solutions that address privacy surrounding sensitive data and cloud service vulnerabilities. These tools help to ensure that security protocols are always up-to-date and effective in mitigating emerging threats. Identity and access management (IAM) solutions, for instance, include user provisioning, authentication, authorization and access management. 

Additionally, software for cloud cost-control helps to continuously automate critical actions in real time, without human intervention, delivering the most efficient allocation of an organization’s computing power, storage and network resources.

A cloud deployment model defines how cloud resources are accessed, managed, and deployed, with options that include the following:

• Public cloud

• Private cloud

• Hybrid cloud

• Multicloud

• Hybrid multicloud

In a public cloud model, a cloud provider offers computing resources like software, virtual machines and infrastructure to users via the internet, on demand and with flexible pricing. The provider manages and owns all hardware and other infrastructure.

This multi-tenant environment allows users to share a pool of virtual resources automatically provisioned for and allocated to individual tenants through a self-service interface. Public cloud is popular for its scalability, cost-efficiency and the ability to minimize on-site infrastructure.

A private cloud is a single-tenant environment that dedicates all resources and infrastructure to one organization, combining the benefits of cloud computing with the control and security of on-premises systems. It’s often used by large organizations or those with strict data privacy needs, and it can be hosted either on-site or by a third-party provider.

It’s worth noting that a private cloud differs from a virtual private cloud (VPC). A private cloud is managed by an organization, while a VPC is a service from a CSP that creates a private cloud-like environment on public cloud infrastructure.

A mix of public, private, and on-premises environments, hybrid cloud infrastructure allows businesses to move workloads between different cloud solution models based on business needs. This approach provides flexibility and cost-efficiency while allowing organizations to meet specific requirements, such as security or performance, for different workloads.

An IBM Institute of Business Value analysis of more than 50 client organizations shows 3 times higher return on investment (ROI) from IT programs over 5 years when organizations adopt hybrid-by-design principles.

The multicloud model involves using multiple cloud services from various providers. It offers organizations the freedom to select the best available technologies, avoiding vendor lock-in and ensuring a wider array of features and services. It also helps mitigate risks related to security, compatibility and compliance.

Today, the majority of enterprise organizations rely on a hybrid multicloud approach. In addition to providing the flexibility to select the most optimal and cost-effective cloud services, this model gives organizations greater control over workload distribution, allowing them to enhance efficiency, boost performance and reduce costs.

There are three main types of cloud delivery models (or service models), which are often used together:

• Infrastructure as a service (IaaS)

• Platform as a service (PaaS)

• Software as a service (SaaS)

Outside of the main three, other popular service models include:

• Serverless computing (serverless)

• Function as a service (FaaS)

Infrastructure as a service (IaaS) provides on-demand access to computing resources (e.g., servers, storage and networking) to support application workloads in the cloud. IaaS helps businesses scale their infrastructure without the high costs of maintaining on-premise data centers.

A platform as a service (PaaS) is a complete cloud platform for developing, running and managing applications. PaaS platforms provide access to operating systems, middleware, databases and development tools. This capability allows organizations to build, test and deploy applications in the cloud instead of investing in the physical infrastructure required to run them.

PaaS simplifies the process of migrating applications to the cloud, either through re-platforming (modifying applications for cloud benefits) or refactoring (rebuilding applications with cloud-native technologies like microservices and containers).

Software as a service (SaaS) provides ready-to-use, cloud-hosted applications (e.g., Zoom, Slack). SaaS eliminates an organization's need for software development and infrastructure management because the cloud service provider handles the installation, configuration and maintenance.

Serverless is a computing model that offloads all the backend infrastructure management tasks—provisioning, scaling, scheduling and patching. Serverless computing allows software developers to devote more attention to the code and business logic specific to their applications.

Function as a service (FaaS) is a subset of SaaS in which application code runs only in response to specific events or requests. With FaaS, everything besides the code—physical hardware, virtual machine operating system and web server software management—is provisioned automatically by the cloud service provider in real-time as the code runs and then is spun back down once the execution is complete. Billing starts when execution starts and stops when execution stops.

The phrase cloud infrastructure is sometimes confused with cloud architecture, but there’s a distinct difference. Like a blueprint for constructing a building, cloud architecture serves as the design plan for implementing cloud infrastructure and delivering apps and services. In contrast, cloud infrastructure refers to the physical and virtual resources (e.g., servers, storage, and networking services) that power cloud infrastructure.

A cloud architect, for instance, is an IT professional who oversees an organization’s cloud computing strategy and works on developing cloud adoption plans and overseeing cloud migration initiatives. Their responsibilities include cloud provisioning—the process of setting up these critical components, along with the cloud-based resources, applications and services, to create a fully functional cloud environment. They also work to align cloud infrastructure with the architecture strategy to meet overall business needs, including performance and cost efficiency.

Cloud infrastructure offers numerous advantages, making it a sought-after solution for businesses seeking to optimize their IT operations and drive innovation:

• Reliability

• Agility and speed

• Scalability

• Elasticity

• Cost-optimization

• Business continuity disaster recovery