Whenever user keeps the session idle for some time, then passivation will occur. We can store the passivation objects either in file system or database. You can configure DSS/prconfig settings to choose which storage you would need. By default all passivated objects gets stored in file system from 5.5 onwards.
Three levels of passivation are there.
Default values are 15,30 and 60 mins respectively. We can modify these default values using prconfig setting.
We need to activate the session inorder to activate the passivated objects.