I have a question when the projected EPSG::4326 and EPSG::900913. OpenLayers uses by default EPSG::4326 using the projection coordinates in decimal format already uses Google Maps with coordinates EPSG::900913 meters.
I saw several examples of creating the map in the projection and display property EPSG::900913 projection in EPSG::4326.
What difference does it make on the map? If I want to record a point in the database will be in the map projection EPSG::900913 in this case.