What is SharePoint?

SharePoint is the web platform inside Microsoft 365 for storing, organising, and sharing files and pages across an organisation. It is the engine behind a surprising amount of what you use every day — Teams channel files, OneDrive personal storage, and most company intranets all run on SharePoint underneath. Understanding SharePoint is understanding a large fraction of how Microsoft 365 actually works.

Why SharePoint matters more than it looks

SharePoint's public brand — the intranet product with news pages and web parts — undersells its real role. In practice, SharePoint is the file and structured-data substrate for the whole Microsoft 365 platform. Every Team's files sit in a SharePoint document library. Every OneDrive is a personal SharePoint site under the hood. Every Loop workspace is stored in SharePoint. Every Copilot ground-on-work-data query is largely a query against SharePoint content.

Files in SharePoint are indexed for enterprise search, secured through Entra ID, protected by Purview sensitivity labels, and now grounded by Copilot. It is the durable data layer under the productivity apps.

What SharePoint provides

Document libraries. File storage with versioning, co-authoring, metadata columns, and granular sharing. Every library is a SQL-backed store with server-side rendering, thumbnail generation, and full-text indexing. Files up to 250 GB (Microsoft's current limit) are supported.

Lists. Structured data tables that behave like a lightweight database, with custom columns (text, choice, date, lookup, person, calculated), views, JSON-based column formatting, and forms. Modern lists include Microsoft Lists as a first-class app on top of the same engine.

Pages and news. Web pages built from drag-and-drop web parts. Used for intranet portals, department pages, project spaces, HR portals, and company news distribution. Modern pages use the SharePoint Framework (SPFx) for custom web parts.

Search. Tenant-wide search across files, pages, lists, and people. Modern search feeds Microsoft Search across Bing, Office, and Copilot; Copilot's work-data grounding is largely powered by SharePoint search under the hood.

Permissions. Fine-grained access at the site, library, folder, item, and (for lists) column level, scoped to Entra ID users and groups. Cascade rules from site to items are the default; unique permissions can be applied at any level (with attendant complexity).

Hub sites. A way to associate multiple sites so they share navigation, branding, and news roll-up. The pattern for building a coherent intranet on top of the "every team is a site" world.

External sharing. Guest access, anonymous links, sharing to specific external users. Governed through the SharePoint admin center and Entra ID B2B settings.

The two site types

Team sites are workspaces for a group of people working together — a department, project, or product. Every Microsoft 365 Group and every Microsoft Teams team is backed by a team site. Members contribute; the collaborative pattern is the default.

Communication sites are designed for broadcasting information to a wider audience — intranet landing pages, HR portals, news hubs. Fewer collaborative features, more polished page layout, viewer-most / editor-few permission model.

The distinction matters at design time (pick the right template) but not at data-model time (both are SharePoint sites with document libraries and lists under the hood).

SharePoint and the rest of Microsoft 365

Teams. Every channel's files live in a folder of the team's SharePoint site. Standard channels share the site's default library; private channels get their own SharePoint site; shared channels share a special multi-tenant-capable site. Teams operations that touch files are really SharePoint operations.

OneDrive. Each user's OneDrive is technically a personal SharePoint site, hidden behind a friendlier UI. Every file you save to OneDrive is a SharePoint document library item. Sharing a OneDrive file uses SharePoint's sharing engine.

Viva Connections. The modern intranet is a SharePoint communication site surfaced inside Teams. Same SharePoint pages, same web parts, same permissions — presented as a first-class Teams tab.

Loop. Loop workspaces store their content in SharePoint. Loop components in a Teams chat are actually files on the sender's OneDrive.

Copilot. Microsoft 365 Copilot's ground-on-work-data feature reads SharePoint files, lists, and pages the user has access to. Every SharePoint permission decision made in the last decade now affects what Copilot surfaces.

SharePoint Online vs SharePoint Server

What you get with Microsoft 365 is SharePoint Online, the cloud-hosted service. SharePoint Server is the on-premises version, still sold and supported but increasingly rare. They share concepts and APIs, but Microsoft is diverging the cloud product with features that never come back to Server — Copilot, Advanced Management, restricted content discovery, most of the modern web-part surface.

For any greenfield SharePoint deployment in 2026 and beyond, SharePoint Online is the answer. Server is a legacy commitment being wound down at Microsoft's cadence.

The operational realities

Three areas of operational complexity that every serious SharePoint deployment has to handle.

Sprawl. Every Team creates a new SharePoint site. Every Group creates a new SharePoint site. Over a few years, a tenant grows tens of thousands of sites, most of them semi-stale, many with over-shared files. Governance tooling — expiration policies, site lifecycle workflows, SharePoint Advanced Management — is not optional at scale.

Permissions drift. A site starts with the group's owners as admins and members as contributors. Over time, unique permissions get applied to specific libraries, folders, and items; sharing links proliferate; guests accumulate. Auditing "who can actually access this file" gets harder every year. Regular permission reviews and Data Access Governance reports are the counterweight.

Search relevance and Copilot readiness. SharePoint search only surfaces what it can index, and only for users with permissions. Poorly organised sites feed poor Copilot responses. Consistent metadata, sensible library structure, and reasonable file naming pay compounding returns as Copilot rolls out.

SharePoint Advanced Management

SharePoint Advanced Management (SAM) is a paid add-on that provides the tooling most large tenants need: Data Access Governance reports (surface over-shared sites, files with broad permissions, likely candidates for cleanup), Restricted Access Control (hide sites from Copilot without changing member access), site lifecycle management, and Business-to-Business Extranet setup.

Not required for basic SharePoint use — every tenant has SharePoint. Required for governance at scale, especially in the Copilot era where oversharing is a real operational problem.

Licensing

SharePoint is included in every Microsoft 365 SKU that includes Teams (which is almost all of them). Storage is capped at 1 TB per tenant plus 10 GB per Microsoft 365 licence, with additional storage available as an add-on.

SharePoint Advanced Management is a per-user add-on, bundled with Microsoft 365 E5 and available standalone on other tiers.

SharePoint Syntex (a companion product for automated document processing with AI) is separately licensed and worth evaluating for high-volume document workflows.

The short version

SharePoint is the file, list, page, and search substrate under Microsoft 365. It runs Teams' files, OneDrive's personal storage, Loop's workspaces, the intranet, and most of what Copilot reads. Team sites are for collaboration, communication sites for broadcast. Sprawl, permissions drift, and Copilot readiness are the three operational disciplines every serious SharePoint deployment needs.

If you put files anywhere shared in Microsoft 365 — even unknowingly — they're almost certainly in SharePoint. Understanding it pays back the time many times over.