How is a nail fixed in the wall due to friction?

When you drive a nail in the wall, it does not make hole, it just push the material of the wall to one side. This displaced material get squeezed by the nail and try to expand back into its original form by applying pressure against the nail. In that case, friction appears between the nail and the wall. Thus, it is friction which holds the nail. This is also why a newly formed concrete wall has less ability to holds the nail.