Differences beetweer .trigger 'refresh' and 'updatelayout'

Differences beetweer .trigger 'refresh' and 'updatelayout'

Hi, in starting programing whit jquery mobile and have a dude about update items created dinamic i use .trigger('create') for make this alive but have a dude about using triger 'refresh' or  'updatelayout' what i must used? 
Thanks forward.!