The short version: OneDrive is your personal work drive, for files only you need. SharePoint is your company's shared storage, for files the whole team works on. Teams is the chat-and-meetings app you spend your day in, and when you share a file in a Teams channel it's actually saved into SharePoint behind the scenes.
All three come with every Microsoft 365 Business plan, so this isn't about buying anything. It's about everyone knowing where things go, which sounds trivial until you've watched a finance team lose a fortnight chasing the right version of a budget spreadsheet.
The one rule that prevents most filing mistakes
If you remember nothing else, remember this: mine goes in OneDrive, ours goes in SharePoint or Teams.
Is this a draft, a personal note, or something only you will ever touch? OneDrive.
Will a colleague need to open it, edit it, or rely on it after you've gone home or left the company? SharePoint or Teams.
That single question, mine or ours, sorts the vast majority of files correctly without anyone needing to understand the technology underneath.
OneDrive: your personal work drive
OneDrive is the modern replacement for the old "My Documents" folder and the USB stick. It's tied to your individual login, you get 1 TB per user on Microsoft 365 Business Standard and Business Premium, and files sync to your laptop so you can work offline.
It's the right home for a draft proposal you're not ready to share, your own working notes, or a downloaded copy of something you're reviewing. You can still share a OneDrive file with someone when you need to, but the file belongs to you. That ownership is the point.
SharePoint: your shared team storage
SharePoint is where your company's real files should live: the documents that belong to a department, a project or the business as a whole, not to any one person. The current price list, your policies, the client folders, the shared templates - all SharePoint.
Files here have proper access control, so the sales team sees sales files and HR keeps payroll private. Several people can edit the same document at once, and version history lets you roll back if someone deletes the wrong thing. And when someone leaves, the files stay exactly where they are, because they were never tied to that person's account in the first place.
Teams: the front end you actually work in
Teams is the app most people live in: chat, calls, video meetings, and channels for each project or department. It's less a storage location and more the place you do the work.
Here's the part that confuses almost everyone. When you drop a file into a Teams channel, that file isn't stored "in Teams" at all. Every Team has a SharePoint site behind it, and each channel gets its own folder there. Share a file in the Marketing channel and it lands in the Marketing Team's SharePoint document library, automatically. Teams is just a friendlier window onto the same shelf. Once that lands, the rest of it makes sense: Teams and SharePoint are two doors into the same room.
The two mistakes we fix most often
1. Master company files living in one person's OneDrive
This is the big one. The office manager builds the staff rota, the master price list and the supplier contacts in their own OneDrive because it's easy and it's right there. Then they hand in their notice. Now those files sit inside a leaver's personal account, and recovering them becomes an urgent, awkward job, often against a 30-day window before the deleted account's OneDrive is cleared. If a file matters to the business, it should never live in a personal drive.
2. The same file in all three places
The other classic is duplication. A document gets saved to OneDrive, emailed round, then re-uploaded to a Teams channel, and within a week nobody knows which copy is the live one. People end up editing three versions in parallel. The fix isn't clever software, it's the discipline of one home per file and sharing a link rather than sending copies around.
A simple structure that works for most SMEs
You don't need anything elaborate. For most businesses we set up:
One SharePoint site (or Team) per department or major project - Finance, Operations, Sales, and so on - so files have an obvious, permanent home with the right people able to reach them.
OneDrive for personal drafts and working files only - the stuff that's genuinely yours and in progress.
Teams for day-to-day collaboration, with each department's channel pointing at its own SharePoint area, so people share files in the chat they already use and everything quietly lands in the right place.
The aim is that a new starter can find the right folder on day one without asking, and nothing important is ever trapped in an individual's account.
Why the setup matters more than the tools
Teams, SharePoint and OneDrive are good products, but they don't organise themselves. Left to grow on their own, they sprawl into hundreds of overlapping channels and orphaned files, and permissions drift until people either can't see what they need or can see things they shouldn't. The difference between a tidy setup and a mess isn't the apps, it's a planned structure, sensible naming and access permissions that match how your business actually works.
That planning is worth getting right early, before bad habits set in. If you'd like a hand designing a file structure that fits your team, or sorting out a Microsoft 365 setup that's already become a muddle, our team is happy to help.