HostingEnvironment.MapPath
HostingEnvironment.MapPath()
TL;DR: always use HostingEnvironment.MapPath()
http://stackoverflow.com/questions/3795986/using-server-mappath-inside-a-static-field-in-asp-net-mvc
Server.MapPath specifies the relative or virtual path to map to a physical directory.
Server.MapPath(“.”)1 returns the current physical directory of the file (e.g. aspx) being executed
Server.MapPath(“..”) returns the parent directory
Server.MapPath(“~”) returns the physical path to the root of the application
Server.MapPath(“/”) returns the physical path to the root of the domain name (is not necessarily the same as the root of the application)