In this section, I wanna talk about the main differences between the public cloud and traditional, on-premises data centers. You may be new to cloud computing, but I am going to assume that you already understand how on-premises data centers operate. I'm going to make several comparisons between it and cloud computing. When building and running your own data center, you have a quite the list of responsibilities. You need to worry about things like picking the right a location. You have to decide where it's going to be physically located. You have to factor in things like the cost of land and property taxes. You need to make sure that you can access reliable power, reliable internet connection, and you need to make sure that you're gonna have enough room for growth in the future.

Next, you're gonna have to think about things like physical Security. This includes both external and internal. So you might have to hire a security team. You're gonna have to install a bunch of locks and cameras and set some alarms. You need to consider things like mechanical and electrical infrastructure. That means you gotta think about things like air conditioning, setting up backup generators and UPS units, and you have to think about things like fire suppression.

Of course, those elements are just part of the building itself. You're also gonna have to fill it with a bunch of hardware. So you're gonna need a bunch of network infrastructure. That means things like switches, routers, and firewalls. You're gonna need the physical machines and servers. This includes both hardware and software. And you're gonna need lots and lots of storage. This includes hard drives, solid state drives, and things like NAS and SAN.

Now, let's look at each of these again, but this time from the perspective of using the cloud. Location. So depending on the size of your company, you might only have one or two data center locations. However, public cloud providers have locations all over the globe. And within each of these regions, they're gonna have at least two data centers. Now, these data centers are kept separate so that if one goes down, the other is gonna be still be up and running. But they're located close enough to each other to ensure high speed interconnectivity.

Physical security. As we've already discovered, the public cloud is operated, managed and maintained by the vendor. As a result, the end user has no access to the physical data center where the resources are located. It's completely the vendor's responsibility to ensure the correct certification and governance regarding security. Public cloud vendors adhere to the most stringent of controls, and for auditing purposes, you can access their compliance certifications online. Mechanical and electrical Infrastructure. Now, mechanical and electrical infrastructure, such as generators, are all situated at the data center itself. So as a result, the same rule applies. This is the vendor's responsibility. So again, this burden is removed from the end user.

Network infrastructure. In the public cloud, you no longer have direct access to the network hardware. There's no longer any way for you to physically install a switch or a router. The cloud vendor is responsible for setting that all up and maintaining that. All physical networking components have been replaced with virtual components. So in order for you to use this, you typically start by creating a virtual network. These virtual networks work pretty similarly to physical networks. You can segment them into different IP address ranges. You can set the different network segments to be either public facing or private. Routing and access control lists can also be configured for enhanced control. And once you have completed your virtual network, you can then provision your resources within these subnets.

Servers. Depending on your vendor, virtual machines are typically referred to as "instances." But just as there are different types of physical servers, vendors offer different types of instances. For example, most providers offer instances that are optimized for running databases. Now, this is part of the benefit of the cloud. The vendors are capable of replicating the same functions that you use today, but usually with a lot more optimization and polish.

Storage. Now, storage is fantastic within the cloud. It's essentially unlimited, it's hugely scalable, and it's highly durable. And as with compute, there are many different storage services, depending on what you need. These include both block-level and object-level storage. So, as you can see, the on-premises data center involves a lot more responsibilities, as well as a number of extra costs. Building your own data center requires significant upfront capital that often needs to be depreciated over a number of years. To help explain this, let me go a little deeper. So there are two main types of expenses in an organization. You have capital expenditures, or CapEx, and operating expenditures, or OpEx. Capital expenditures are major purchases that your company makes over the long-term. Operating expenses are the day-to-day expenses. So purchasing a company car would be a capital expense. Renting a car would be an operating expense. Capital expenditures generally can be a great way to save money when your needs are predictable. But unfortunately, business needs are rarely predictable. Will that new database server you just bought today work as well in two years? How many software licenses are you actually gonna be using six months from now? By leveraging the cloud, you can exchange your capital expenditures for operating expenditures. This "consumption-based model" can give your business the agility it needs to stay competitive in an ever-changing market. I have only skimmed the surface of the available services within the public cloud. Certain vendors will offer much, much more. However, I just wanted to point out how migrating your existing systems to a public cloud can bring significant benefits.