This page describes parameters under the "Visuals" foldout that are shared between all AO modes.
Fadeout
Defines the distance (in meters) at which the occlusion effect fades out. Setting this value to 0 disabled fadeout completely, letting AO be visible at any distance.
Performance impact: insignificant
Intensity
Guides the final intensity of the ambient occlusion, higher values result in darker ambient occlusion.
For HDRP this corresponds to the Intensity of the SSAO override.
For URP this corresponds to the Intensity of the SSAO renderer feature.
Performance impact: none
Direct Lighting Occlusion
Defines how visible the effect is in areas exposed to direct lighting. It's recommended to use 0 for maximum physical accuracy.