In the file settings box you can select the default ppi for SVG files and default dpi for bitmaps.
- Inkscape v0.91 and older: 90ppi
- Inkscape v0.92 and newer: 96ppi
- Adobe Illustrator: 72ppi
* Note that there was a brief cutover in Inkscape around v0.90 beta where they switched temporarily from 90 to 96 before going back to 90 again for v0.91. When in doubt, run the latest version.
For Bitmap raster image resolution, this can vary depending on your preferred output settings from your graphics program.