Microsoft Fabric & OneLake Explained in 2026

When people talk about Microsoft Fabric, you might have heard terms like workspaces, capacities, domains, items, and tenants. And then there is OneLake and these different data stores like lakehouses and warehouses. But maybe you're not fully sure how all of these connect and tie together and what they really mean. Don't worry, this video is here to help. We're going to break down the structure and terminology of Microsoft Fabric in simple and easily understandable way. Stay tuned for more. Welcome to the video. My name is Alex and I'm a data architect and Microsoft data platform MVP. And on this channel I cover Microsoft Fabric related topics. In this video we are going to learn about the structure and basic concepts of Microsoft Fabric and how those different concepts like capacities, workspaces, and items relate to each other. Also, we are going to learn about OneLake that is underlying data store behind Fabric. But now let's get started. Let's start by covering the core terminology and structure of Fabric. If you're working in a Microsoft Fabric environment, you will hear terms like tenant, capacity, workspace, domain, and subdomain, etc. thrown around. And if you're not familiar what those terms mean in Fabric context, those conversations can feel quite confusing. But now let's break down this Fabric rabbit hole so that those terms don't feel so scary anymore. Let's start this rabbit hole from Microsoft Entra tenant. Basically, if you're using any of Microsoft cloud services, you have to have a tenant. You can think of tenant as a dedicated playground that Microsoft has given for your organizations to build your services into. Also, with a tenant, you get some identity and access management for your organization. For example, if the company you are working for is using Microsoft cloud services like Microsoft 365 services that cover very commonly used services like Outlook, Word, Excel, and Teams, you know that you can use organizational account, meaning basically your email, to log in to all of those services. And that is made possible by having a tenant on the background. You could say that tenant is like a backbone for all of your Microsoft services. So, basically, very briefly summarizing, tenant is a control center for managing users and security across Microsoft cloud services. There is also a possibility that organizations could have multiple tenants, but let's not complicate this example with those, and for now it is good to know that that is just possible.