The file extension RELS is associated with Microsoft Office, which is a suite of office productivity applications commonly used with the Windows operating system. RELS files are relationship files that describe the order of documents which are created with MS Office as well as the structure of different portions of each document.
RELS files are a document file type in XML format that contains data which points to various parts of the document to describe the complete structure. The data describes the association for document objects and how they relate to one another and stores any necessary permissions for document access.
XML stands for Extensible Markup Language, which is a programming language that provides an efficient method for organizing and presenting information to the end user. For this reason, RELS file extensions use XML to allow the document to be opened and viewed in its proper order and format.
How to Open RELS Files
Since the RELS file extension uses XML, the Extensible Markup Language is written in ASCII plain text format. This means that you can open and view the contents of a RELS file using any text editor such as Notepad or WordPad for Windows, Apple TextEdit for Mac, or gEdit and Nano Editor for Linux.
If you use Windows, you can open RELS files using components from the Microsoft Office Suite 2010. The three applications which are commonly used to open RELS files are Microsoft Word, which is a word processing application, Excel spreadsheet, or the PowerPoint presentation application. You can also use MS Outlook or MS Works to open RELS files in Windows.
If you use Mac OS X, you can open RELS files using Microsoft Word 2011, Excel 2011, or PowerPoint 2011. All three applications are part of Microsoft Office 2011 for Mac.
RELS files can also be created by OpenOffice with the XML data generated by the word processing application. OpenOffice is an open source suite of office productivity applications available as a free download on the OpenOffice.org website.
OpenOffice is a multiplatform application that is compatible with Windows, Mac, and Linux. You can open RELS files using the OpenOffice Write module, spreadsheet application, or the presentation program.
RELS files can also be associated Customer Relationship Management software produced by ACT! This is a software application which offers a database for multiple users to access simultaneously. ACT! CRM stores client information in files that contain the RELS extension. This type of RELS file can be opened on PCs that have access to ACT! CRM or by using Microsoft Office Excel or OpenOffice spreadsheet.