Data Files Extensions - What are data files and how do I open a data file?

What are data files and how do I open a data file?

File Type Category File Format
.abs Data Files Absolute Database File
.adf Data Files ESRI ArcInfo Binary Grid Format
.alf Data Files ACT! Lookup File
.bok Data Files TestGen Testbank File
.cgf Data Files Crytek Geometry Format File
.csv Data Files Comma Separated Values File
.d01 Data Files VirtualDrive Disc Image Part 2 File
.dat Data Files Data File
.ddb Data Files Digidesign Database
.dsb Data Files Wondershare DVD Slideshow Builder Project
.dz Data Files Dzip File
.ecm Data Files ECM Disc Image
.emb Data Files Wilcom Embroidery Design File
.ev3 Data Files Team Manager Meet Event File
.exv Data Files Adobe Extension Script
.galleryitem Data Files SMART Notebook Gallery Item File
.gnp Data Files GNPeak Output File
.graphml Data Files GraphML File
.ifaith Data Files iFaith SHSH File
.irx Data Files Brewer Irradiation File
.jasper Data Files JasperReports Data File
.jrprint Data Files JasperReports Print File
.ldf Data Files SQL Server Transaction Log File
.llb Data Files LabVIEW Library File
.lrcat Data Files Adobe Photoshop Lightroom Catalog File
.ndk Data Files Lotus Notes Design Elements File
.nrl Data Files Autonomy Interwoven Link File
.nv2 Data Files NewViews 2 Database File
.one Data Files OneNote Document
.pdx Data Files Adobe Acrobat Index File
.pmm Data Files Pegasus Mail Mailbox File
.pos Data Files Trimble Position File
.psa Data Files Photoshop Album Catalog File
.ptn Data Files PaperPort Thumbnail File
.pxc Data Files Photodex Cache File
.qvd Data Files QlikView Data File
.rbt Data Files Lego MINDSTORMS NXT Program
.rda Data Files R Data File
.rdb Data Files N64 ROM Database
.rpt Data Files Crystal Reports File
.rvdata Data Files RPG Maker VX Data File
.rxdata Data Files RMXP Data File
.sam Data Files Ami Pro Document
.schematic Data Files MCEdit Schematic File
.sgn Data Files Slax Boot File
.sim Data Files SAP Tutor File
.smm Data Files Samsung Memo File
.tde Data Files Tableau Data Extract File
.uds Data Files Sierra Generations File
.uea Data Files Protector Suite QL Encrypted Archive
.update Data Files ISAPI Update File
.vdf Data Files AntiVir Virus Definitions File
.wfm Data Files Tektronix Waveform Data File
.xrff Data Files Extensible Attribute-Relation File Format