Word, Excel & PowerPoint explained
A plain-English guide to the three core Microsoft Office apps — what each one does, when to use it, and how to get started.
- Difficulty
- Beginner
Word, Excel, and PowerPoint are three of the most widely used business apps in the world. Every Microsoft 365 business plan includes the browser versions. The installable desktop apps come with some plans and not others — see Web vs desktop apps below.
Quick summary
Word is for documents — letters, reports, proposals. Excel is for numbers and data — budgets, lists, calculations. PowerPoint is for presentations — slides with text, images, and charts. All three work in your browser without any installation, and files you keep in OneDrive save as you work and hold a version history you can roll back to.
Microsoft Word
Word is a word processor — it's designed for creating and editing text-based documents.
Common uses:
- Business letters and proposals
- Reports and whitepapers
- Contracts and agreements
- Meeting agendas and minutes
- Any long-form written document
How to open it: Go to microsoft365.com — which now opens at m365.cloud.microsoft — sign in with your work account, then pick Word from the app launcher. Or, on your computer, open the Word desktop application.
Saving your work: Word documents are saved as .docx files. If you use Word on the web, your file is saved automatically to OneDrive. In the desktop app you choose where to save it; once the file lives in OneDrive or SharePoint, AutoSave is on by default and saves your changes every few seconds as you work.
Microsoft Excel
Excel is a spreadsheet application — it organizes data into rows and columns, and can calculate, analyze, and visualize that data.
Common uses:
- Budgets and financial forecasts
- Invoices and expense tracking
- Inventory lists
- Project timelines and task lists
- Simple databases (contacts, products, etc.)
Key concept — formulas: Excel can perform calculations automatically. For example, if you type numbers in a column, you can add a formula at the bottom that sums them all. Excel ships with hundreds of ready-made calculations, which Microsoft calls functions — everything from simple addition to statistical analysis.
How to open it: Go to microsoft365.com and pick Excel from the app launcher, or open the desktop application.
Excel files are called workbooks
An Excel file is called a workbook. A workbook can contain multiple worksheets — the sheet tabs along the bottom. Each worksheet is a grid of rows and columns, and the individual boxes are called cells.
Microsoft PowerPoint
PowerPoint is a presentation tool — it creates slideshows for meetings, pitches, training, and more.
Common uses:
- Client presentations and pitches
- Team meetings and all-hands briefings
- Training materials
- Marketing decks
Key concepts:
- A file is called a presentation
- Each screen is a slide
- You present slides in order. In the desktop app, press F5 on Windows to start from the beginning (on a Mac it is Command+Shift+Return), or open the Slide Show tab and start from there
- Slides can contain text, images, charts, videos, and shapes
How to open it: Go to microsoft365.com and pick PowerPoint from the app launcher, or open the desktop application.
Web vs desktop apps
Web apps (included with every Microsoft 365 business plan)
- Work in the current version of Edge, Chrome, Safari or Firefox
- No installation needed
- Auto-save to OneDrive
- Slightly simpler features
- Great for most everyday tasks
Desktop apps (Business Standard, Business Premium or Microsoft 365 Apps for business)
- Installed on your computer
- Full feature set
- Works offline
- Better for complex documents and spreadsheets
- Not included with Business Basic, which covers the web and mobile apps
For most writing, budgeting, and basic presentations, the web apps are perfectly capable.
Common questions
Can I open old Office files (.doc, .xls, .ppt)?
Yes, with one wrinkle worth knowing. The desktop apps open the older formats, but they open them in Compatibility Mode, which switches off newer features so that someone still on the old version of the app can edit the file. The file stays in the old format until you convert it on purpose — in Word, that is File → Info → Convert.
Word on the web is stricter: a .doc file opens read-only, and when you try to edit it Word offers to make a .docx copy for you to work in.
Can I share my Word documents with people who don't use Microsoft 365?
Yes. You can share a link from OneDrive (they can view or edit in their browser), or download a PDF copy to send as an attachment. A PDF looks the same on most computers, and most modern browsers can open one without any extra software. One caveat: a PDF is not locked — Word itself can open and edit PDFs, so sending a PDF does not stop someone changing it.
What is a template?
A template is a pre-formatted file you can start from, rather than building a document from scratch. Microsoft includes free, pre-built templates in the apps — calendars, business cards, letters, brochures, newsletters, resumes, presentations and more. In the desktop apps they appear when you choose File → New. There is a larger collection at create.microsoft.com.
How do I convert a Word document to PDF?
It depends which Word you are in.
- Word on the web: File → Export, then Download as PDF (there is also Download as PDF with comments if you want the comments included).
- Word on Windows: File → Save As (or Save a Copy if the file is already saved), select Browse, choose PDF from the file-type drop-down, then Save.
- Word on a Mac: File → Save As or Save a Copy, then File Format → PDF.
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