The Simple Definition: A way of building software in small steps, getting feedback often, and fixing things as you go, rather than planning everything perfectly at the start.

Why It Matters for Business: You get a usable product faster. Instead of spending six months building something nobody wants, you build a small part, test it with users, and adjust. It reduces financial risk.

The Simple Definition: A digital receptionist for your software. It takes requests from users (like "log me in") and directs them to the exact service that handles that task.

Why It Matters for Business: It secures your data by controlling who can access what, and it prevents your system from crashing by managing traffic spikes.

The Simple Definition: The final product created by the build process, like a ZIP file or a Docker image, ready to be deployed.

Why It Matters for Business: It's the "package" you ship to customers. Managing artifacts correctly ensures you know exactly what version of software is running where.

The Simple Definition: A prioritized to-do list of features, bug fixes, and tasks that the team needs to work on.

Why It Matters for Business: It ensures the team is always working on the most valuable tasks first, aligning development effort with business goals.

The Simple Definition: A safety technique where you run two identical versions of your app (Blue and Green). You update the idle one, test it, and then switch all users to it instantly.

Why It Matters for Business: Zero downtime. If you deploy a new feature and it breaks, you can switch back to the old version instantly. It removes the fear of "breaking production."

The Simple Definition: Releasing a new update to a small group of users (like 5%) first to see if it works before giving it to everyone.

Why It Matters for Business: It limits the damage of a bad update. If there's a bug, only a handful of people see it, not your entire customer base.

The Simple Definition: Intentionally breaking things in a controlled way (like turning off a server) to see if the system recovers automatically.

Why It Matters for Business: It builds confidence. By breaking things on purpose during the day, you ensure your system can handle unexpected failures at 3 AM without waking anyone up.

The Simple Definition: An automated assembly line for your code. "CI" tests code changes automatically. "CD" releases them to your servers automatically.

Why It Matters for Business: You can release features daily instead of monthly. It removes manual errors and lets your team focus on building, not fixing broken deployments.

The Simple Definition: Building applications specifically to run in the cloud (using containers, microservices), rather than just moving old servers to a cloud provider.

Why It Matters for Business: It unlocks the true scalability and cost-savings of the cloud. Old apps in the cloud are just expensive; cloud-native apps are efficient and resilient.

The Simple Definition: A group of servers (computers) working together as a single system to run applications.

Why It Matters for Business: Clusters provide power and reliability. If one server in the cluster fails, the others take over, keeping your business online.

The Simple Definition: Automated checklists for setting up servers. Instead of an engineer manually installing software on 100 servers, a script does it automatically.

Why It Matters for Business: It ensures every server is identical (consistency), reducing bugs caused by "human error," and speeds up setting up new environments.

The Simple Definition: Packaging an application with everything it needs to run (code, libraries, settings) into a single box (container) that runs the same everywhere.

Why It Matters for Business: It eliminates the "it works on my machine" excuse. If it runs in a container, it runs on your server, your laptop, or the cloud. This speeds up development significantly.

The Simple Definition: Deployment is installing the software on a server. Release is making it visible to users.

Why It Matters for Business: You can deploy code safely in the background, test it, and then "release" it to customers only when you are 100% sure it works.

The Simple Definition: A culture shift where the team building the software (Dev) and the team running it (Ops) work together, sharing responsibility for the product's success.

Why It Matters for Business: It breaks down silos. Teams stop blaming each other and start collaborating to ship better software faster.

The Simple Definition: Integrating security checks into the DevOps process from the very beginning, rather than checking for security at the end.

Why It Matters for Business: Fixing security holes before the software is built is cheap. Fixing them after a hack is expensive. It protects your brand reputation.

The Simple Definition: A set of tools used to collect, search, and visualize logs (records of what happened) from your systems.

Why It Matters for Business: It helps your team find the "needle in the haystack" when troubleshooting errors, drastically reducing downtime.

The Simple Definition: A switch in the code that allows you to turn features on or off without deploying new code.

Why It Matters for Business: You can launch a feature to 10% of users to test it, or turn off a broken feature instantly without downtime.

The Simple Definition: The practice of managing cloud costs. It brings financial accountability to the variable spending model of the cloud.

Why It Matters for Business: The cloud can get expensive fast. FinOps ensures you are paying for value, not waste, and helps you predict your monthly bills.

The Simple Definition: Using Git (where code is stored) as the remote control for your infrastructure. If you want to change a server setting, you change a file in Git, and an automated tool makes it happen.

Why It Matters for Business: It creates a perfect audit trail of who changed what and when. It also allows you to revert changes instantly if something breaks, just by undoing a Git commit.

The Simple Definition: A dashboard tool that turns complex computer data into easy-to-read charts and graphs.

Why It Matters for Business: It gives you a real-time "cockpit view" of your business's technical health, so you can spot trends or problems at a glance.

The Simple Definition: Designing a system so it almost never goes down, even if parts of it break.

Why It Matters for Business: Downtime costs money. HA ensures your digital doors are always open for customers.

The Simple Definition: Using a mix of your own private servers (on-premise) and public cloud services (like AWS or Azure) together.

Why It Matters for Business: It offers flexibility. You can keep sensitive data on your own secure servers while using the public cloud's power for heavy computing tasks.

The Simple Definition: A property where running a command multiple times produces the same result as running it once (e.g., "Make sure the light is on").

Why It Matters for Business: It prevents errors in automation. If a script runs twice by accident, it won't break your system or charge a customer twice.

The Simple Definition: Managing your servers and networks using code files (text) instead of manually clicking buttons in a dashboard.

Why It Matters for Business: You can rebuild your entire business infrastructure in minutes. It makes your setup consistent, auditable, and disaster-proof.

The Simple Definition: Never updating a server once it's running. If you need to change something, you destroy the old server and build a new one with the changes.

Why It Matters for Business: It prevents "configuration drift" where servers become different over time, leading to mysterious bugs. It ensures consistency and reliability.

The Simple Definition: A "traffic controller" for your containers. It automatically manages where they run, restarts them if they crash, and scales them up when traffic spikes.

Why It Matters for Business: It allows you to run massive, complex applications with a small team. It ensures your app stays online no matter what happens to the underlying servers.

The Simple Definition: The delay between a user's action (clicking a button) and the application's response.

Why It Matters for Business: High latency means a slow website. Slow websites frustrate users and drive them to competitors.

The Simple Definition: Distributing incoming website traffic across multiple servers so no single server gets overwhelmed.

Why It Matters for Business: It prevents your website from crashing during high traffic events (like Black Friday) and ensures a fast experience for every user.

The Simple Definition: The average time it takes to fix a broken system and get it back online.

Why It Matters for Business: It's a key metric for resilience. The lower the MTTR, the less money you lose during an outage.

The Simple Definition: Breaking a large application into small, independent pieces that talk to each other (e.g., one piece for login, one for payments).

Why It Matters for Business: You can update one part of your app without risking breaking the whole site. Different teams can work on different parts simultaneously, speeding up innovation.

The Simple Definition: Building an application as one giant, single block of code. The opposite of microservices.

Why It Matters for Business: It's easier to start with, but as your business grows, it becomes very hard and risky to update. A small change requires re-deploying the entire system.

The Simple Definition: Monitoring tells you when something is wrong (red light). Observability allows you to ask why it went wrong by looking at the data.

Why It Matters for Business: Monitoring alerts you to downtime. Observability helps you fix it quickly so you can get back to business.

The Simple Definition: Automated coordination of complex computer systems and services (like a conductor leading an orchestra).

Why It Matters for Business: It allows you to manage massive, complex applications with a small team by automating the "traffic control" of data and services.

The Simple Definition: A set of automated steps that code goes through to get from a developer's computer to production.

Why It Matters for Business: It standardizes quality. Every piece of code goes through the same rigorous testing before reaching customers.

The Simple Definition: A popular tool that watches your systems and records metrics (numbers like CPU usage or memory) over time.

Why It Matters for Business: It is the industry standard for monitoring modern cloud apps. It alerts you to problems before your customers notice them.

The Simple Definition: The process of setting up IT infrastructure (servers, networks, databases) so it is ready to use.

Why It Matters for Business: Automated provisioning (using tools like Terraform) speeds up project start times from weeks to minutes.

The Simple Definition: Testing to make sure that a new software change didn't accidentally break existing features.

Why It Matters for Business: It protects your reputation. It ensures that fixing one bug doesn't create two new ones.

The Simple Definition: Reverting to the previous version of software if the new version has problems.

Why It Matters for Business: It's an "undo" button for deployments. It minimizes the impact of bad updates on your customers.

The Simple Definition: Scalability is the ability to handle growth (adding more servers permanently). Elasticity is the ability to grow and shrink automatically based on demand (like during a sale).

Why It Matters for Business: Scalability ensures you can grow your business. Elasticity ensures you don't pay for idle servers when customers aren't using them.

The Simple Definition: Vertical is making a single server bigger (more RAM). Horizontal is adding more servers.

Why It Matters for Business: Horizontal scaling is usually better for cloud apps because it's limitless and more reliable (if one server dies, others exist).

The Simple Definition: Running code without managing any servers. The cloud provider handles everything; you just upload code.

Why It Matters for Business: You pay only when your code runs. No traffic = zero cost. It's the ultimate efficiency for sporadic tasks.

The Simple Definition: A dedicated infrastructure layer that controls how different parts of an application share data with one another. It handles things like traffic encryption and load balancing automatically.

Why It Matters for Business: As you add more microservices, communication gets messy. A service mesh organizes this traffic, making your application more secure and easier to monitor without rewriting code.

The Simple Definition: Moving tasks like testing and security checks to the beginning (left side) of the development timeline, rather than doing them at the end.

Why It Matters for Business: Finding a bug or security flaw while writing code takes minutes to fix. Finding it after release can cost millions in downtime and reputation damage.

The Simple Definition: Attaching a small "helper" container to your main application container to handle tasks like logging or security.

Why It Matters for Business: It keeps your main application code clean and focused on business logic, while standardizing how you handle operations across all apps.

The Simple Definition: A "photo" of a server or database at a specific moment in time.

Why It Matters for Business: It's crucial for backups. If data gets corrupted, you can restore the system to exactly how it was in the snapshot.

The Simple Definition: A part of a system that, if it fails, stops the entire system from working.

Why It Matters for Business: It is a major risk. Identifying and removing SPOFs ensures your business stays online even if a component breaks.

The Simple Definition: Applying software engineering principles to operations problems. SREs are responsible for keeping the site reliable and scalable.

Why It Matters for Business: They ensure your site stays up during Black Friday traffic. They balance the need for new features with the need for stability.

The Simple Definition: Stateless apps don't remember past interactions (like a Google search). Stateful apps remember data (like a shopping cart).

Why It Matters for Business: Stateless apps are much easier and cheaper to scale. Designing for statelessness where possible saves money.

The Simple Definition: The implied cost of additional rework caused by choosing an easy (limited) solution now instead of using a better approach that would take longer.

Why It Matters for Business: Like financial debt, you have to pay interest (slower development later). If you don't pay it down, your team spends all their time fixing old code instead of building new features.

The Simple Definition: A popular tool for Infrastructure as Code. It works with AWS, Azure, and Google Cloud.

Why It Matters for Business: It prevents "vendor lock-in" to a degree and is the industry standard for defining cloud infrastructure.

The Simple Definition: The percentage of time a system is operational and accessible to users.

Why It Matters for Business: It is the most visible measure of reliability. 99.9% uptime means your business is open; 50% means you are losing customers.

The Simple Definition: Being so dependent on one cloud provider (like AWS) that moving to another (like Azure) is extremely difficult and expensive.

Why It Matters for Business: It affects your negotiating power and long-term flexibility. Using open standards (like Kubernetes) helps reduce this risk.

The Simple Definition: A system that records changes to a file or set of files over time so that you can recall specific versions later.

Why It Matters for Business: It's a time machine for your project. It prevents data loss, enables collaboration, and provides a history of every change made.

The Simple Definition: Creating virtual versions of a computer. It allows you to run multiple "computers" (VMs) on one physical machine.

Why It Matters for Business: It maximizes hardware usage and saves money on physical servers. It is the foundation of cloud computing.

The Simple Definition: A human-readable language used to write configuration files for tools like Kubernetes and Ansible.

Why It Matters for Business: It is the standard language for defining infrastructure, making it easy for humans to read and write configurations.

The Simple Definition: A security model that assumes no user or device is trustworthy, even if they are inside the company network. Every request is verified.

Why It Matters for Business: Traditional security is like a castle moat; once you're in, you're trusted. Zero Trust protects you even if a hacker gets inside the network, limiting the damage they can do.