Both are described here
Talk - Is used in combination with the Effects button at the bottom of the Waypoints Dialogue. The group's leader will speak the given Voice phrase, complete with lip movements. The group does not move to the waypoint's location, instead skipping immediately to the next waypoint.
Scripted - This waypoint type will execute the script file that is in the "Script" box on the bottom of the waypoints screen. Enter the file name directly, without any exec type command or quotation marks, then up to 4 arguments in an array. The group will not move to the waypoint location. The group will wait until the external script exits before moving on to the next waypoint. An argument array is passed to the script in the form [<group leader>,<waypoint position array>,<object waypoint is attached to>,<user array element 0>,<user array element 1>,<user array element 3>,<user array element 4>]. Note the On Activation script code block can be used to execute any script at any waypoint, making this waypoint type somewhat redundant.