Google Files Extensions - What are google files and how do I open a google file?

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

File Type Category File Format
.crx Google Files Chrome Extension
.gdoc Google Files Google Drive Document
.gslides Google Files Google Drive Presentation
.kmz Google Files Google Earth Placemark File
.localstorage Google Files WebKit Local Storage Data File
.lod Google Files Heroes of Might and Magic 3 Graphics File
.obb Google Files Android Opaque Binary Blob File
.rom Google Files N64 Game ROM File