System.Configuration.ConfigurationManager

Added in .NET 2.0
This property gets a read-only collection of the settings.

System.Confliguration.ConfigurationManager.AppSettings 

ConfigurationManager.GetSection(string) 

GetSection - retrieves a specified configuration section from the current applications default configuration

System.Configuration.ConfigurationManager.GetSection("applicationSettings/"------".MySettings) 

System.Configuration.ConfigurationSettings

Added in .NET 1.1
This property gets a read-only collection of the settings.

System.Configuration.ConfigurationSettings.AppSettings