Programs & Apps for Work
Office software includes word processing, spreadsheets, presentations, even databases. Most people are familiar with Microsoft Office.
Note this short list of free alternatives include web-based versions of Word, Excel, PowerPoint & more.
This is not an exclusive list of suites; there are more web and desktop alternatives to Office but I see these as the most widely used at this point (2015). The first two of these install on a Windows (and some do on Macs, too); the last two are web apps and require Internet access, but can store files both in the Cloud and on your computer or removable storages, like flash drives.
Suites that install on Windows PCs
Open Office - may the most popular free Office-replacement suite for the PC
LibreOffice - A full suite of Office replacement programs
Web-based Office Alternatives
Google Docs, Sheets & Slides, Drive & more - Google offers web apps for about every common type of application - and 15 GB of cloud storage is included for free - can translate Word & Excel files - but not every feature - and probably PowerPoint, too
Live.com - Microsoft offers web versions Word, Excel, PowerPoint & more for free - like Google, a free account is required - but any email address will work
Note that every version of Windows comes with two basic document tools.
Notepad - for reading & editing plain text files
WordPad - will create basic documents with scalable fonts, line-spacing options, paragrapgh & page formatting, and more
Where are they?
Through Windows 7, they are installed by default under Start (button) - All Programs - Accessories
With Windows 8, use Search "Notepad" or "WordPad"
It is the angst of every Windows user that, when upgrading or moving to a newer version, familiar things move, change or, in some cases, disappear altogether.