So why use mainframes? Because no two businesses are alike, even competitors in the same field. Mainframes need to be open, adaptable and ever-evolving. And that's before we even talk about the processing power, or the system capacity. Because mainframes the built for business, they need to support anything a business could possibly want as part of their business model. When the first companies started using Linux, Linux became a supported operating system. When open source software and hybrid cloud models started becoming part of the way work gets done. You started seeing APIs and cloud-ready solutions appear on the Mainframe. What I'm getting at here is, is that if it's important, you'll find it here on the mainframe. So for example, let's talk about Linux for a minute. Because this is a great example of something that runs really well on Z. Linux runs great on my rented Cloud instance, it runs great on the server under my desk, it even runs on my Raspberry Pi. So why do I want to run Linux on the mainframe, is it going to run any better? Well, what if I could make a Linux instance with 15 processors and a couple gigs of memory? And I also wanted to access 32 different storage area networks and a couple of different network VLANs. Well, I can get that big powerful Linux system. But I can also run that Linux with all of its data being encrypted, at all times, through pervasive encryption. So that's possible and that's pretty cool. I could build five more of those same exact servers, without needing five times the physical resources because of virtualization. That's a huge bonus. I can even bring up Linux Docker instances within the z/OS operating system, where they can run right next to z/OS applications. So I don't need a full system image, if there's just one specific application in need. Part of the big reason for running things on the mainframe is consolidation. Now companies are always looking for ways to save money on operations. So in addition to being able to bring all of those compute resources, like the CPU and memory into one big box. Companies are also able to consolidate things like power supplies, networking adaptors and cooling. Having one larger efficient cooling unit in a mainframe, is much better than having 300 individual CPU fans out there. In business, you'll often find two major types of transactions happening. There's real time transactions, that's like stuff that is reactionary, event-based, needs-to-happen right now. That's stuff like swiping a credit card, making a purchase, changing your insurance policy. That stuff needs to happen instantly. And then there's batch processes, which we've talked about a little bit before. But that kind of summarizes changes in actions that have happened during a period of time. Like figuring out paychecks, or figuring out your phone bill for the month, those are batch processes. The mainframe excels in doing both, from a performance security and a data integrity point of view. Just to give an idea about how prevalent the mainframe is and what a powerhouse it is in business. They power 68% of the world's production workloads, 68%. That's that's more than half, its quite a bit more than half, yeah, it's two-thirds, that's more than two-thirds. So despite running two-thirds of the world's production workloads, they take up only 6% of the total IT cost. Think about that, 6%, to run 68%, okay, I'm a little bit biased. But I happen to think that even if I wasn't sitting in an IBM studio right now, that would still impress me. And that's why I'm so excited you're here to learn all about the IBM Z. You'll walk into a job interview and tell them, you know Parallel Sysplex, IODF configs. You put down on a résumé that you know about z/OS components and how to manage mainframe security. You're putting yourself in a great place. I hope you're having fun, I know I am, because these skills are great ones to have.