After choosing the cloud service model and the cloud type offered by vendors, customers need to plan the infrastructure architecture. The infrastructure layer is the foundation of the cloud. This layer consists of physical resources that are housed in Regions, Zones and Data Centers. A Cloud provider’s IT environment is typically distributed across many Regions around the world. A cloud Region, is a geographic area or location where a Cloud provider’s infrastructure is clustered, and may have names like NA South or US East. The cloud Regions are isolated from each other so that if one Region was impacted by a natural disaster like an Earthquake, the Cloud operations in other Regions would keep running. Each Cloud Region can have multiple Zones (or Availability Zones or AZ for short), which are typically distinct Data Centers with their own power, cooling and networking resources. These Zones can have names like DAL-09 or us-east-1. The isolation of zones improves the cloud’s overall fault tolerance, decreases latency, and avoids creating a single shared point of failure. The Availability Zones (and DataCenters within them) are connected to other AZs and regions, private datacenters and the Internet using very high bandwidth network connectivity. A cloud Data center is a huge room or a warehouse containing cloud infrastructure. These data centers contain pods and racks or standardized containers of computing resources such as servers, as well as storage, and networking equipment - virtually everything that a physical IT environment has. Computing Resources: Cloud providers offer several compute options – Virtual Servers, Bare Metal Servers, and “Serverless” computing resources. Most of the servers in a cloud datacenter run hypervisors to create virtual servers or virtual machines (also called VMs for short), that are software-based computers, based on virtualization technologies. Other servers in the racks are bare metal servers that are physical servers that aren’t virtualized. Customers can provision VMs and Bare Metals servers as and when they need them and run their workloads on them. Cloud users can also run their workloads on serverless computing resources, which are an abstraction layer on top of virtual machines. We will talk about all three compute options in greater detail in subsequent videos. Storage: Information and data can consist of files, code, documents, images, videos, backups, snapshots, and databases and can be stored in many different types of storage options on the Cloud. Bare Metal Servers and Virtual Servers are provisioned with default storage in local drives. Since these cloud servers can be provisioned and decommissioned by customers on demand and freed up for use by other users, any information stored in a local drive can be lost when you delete or decommission a cloud server. However there are other storage options available on the cloud to persist data that you can choose depending on factors like how important your data is, how quickly you want to be able to access it, how often you access it, and how secure you need it to be. These additional storage options include Block storage, File storage, and Object storage. Block and file storage modes are commonly used in traditional data centers, but “often struggle with scale, performance and distributed characteristics of cloud.” Object storage is the most common mode of storage in the cloud as it’s both highly distributed and resilient. We will examine Object Storage and the other storage options in more detail in later videos. Networking: Networking infrastructure in a cloud datacenter includes traditional networking hardware like routers and switches, but more importantly for users of the Cloud, the Cloud providers have Software Defined Networking (or SDN) options where certain networking resources are virtualized or made available programmatically, through APIs. This allows for easier network provisioning, configuration, and management in the cloud. When servers in the cloud are provisioned, you need to setup their public and private network interfaces. The public network interfaces, as the name suggests, connect the servers to the public internet, whereas the private ones provide connectivity to your other cloud resources and help keep them secure. As in the physical IT world, network interfaces in the cloud need to have IP addresses and subnets either assigned automatically or configured. In a cloud environment it is even more important to configure which network traffic and users can access your resources, which can be done by setting up Security Groups and Access Control Lists (or ACLs). For further security and isolation of your resources in the cloud, most Cloud providers provide Virtual Local Area Networks (VLANs), Virtual Private Clouds (VPCs), and Virtual Private Networks (VPNs). Some of the traditional hardware appliances such as firewalls, load balancers, gateways and traffic analyzers can also be virtualized and made available as services in the cloud. Another networking capability provided by the Cloud Providers is Content Delivery Networks or CDNs, that distribute content to multiple points throughout the world so users accessing the content can access it more quickly by getting it from a point nearest to them. We will learn more about some of these cloud networking options and terminology in subsequent videos. Cloud infrastructure is constantly advancing and improving. In the next video, we explain virtualization and virtual machines.