Formation and apostolate

What is the major difference between formation houses and houses of active apostolate?  Or in other words, between formation and apostolate?  

I know I'm splitting hairs.  I am also very aware and conscious of the fact that the two are not different or segregated.  Nonetheless, there is a difference.  There should be a difference.  

During the discussions about getting familiarised with the GC29 documents it occurred to me that perhaps one thing that distinguishes formation from active apostolate is the degree of accompaniment.  While formation is all about accompaniment, during the initial years of formation, the young Salesian is offered a greater possibility of being accompanied.  During apostolate in full-fledged active communities, the level of accompaniment is significantly lower.  Of course, no accompaniment at this stage is bad; the fact is that the luxury formation settings provide for the type of accompaniment offered is not possible in communities with multiple sectors and works.  

Blessed are those who realise that formation is all about accompaniment; helping the young Salesian personalise the formation process so that no matter where he goes or does, he makes that an opportunity for learning and growing.  Just like Don Bosco who did not treat his seminary years as years of formation;  his whole life, every incident, every achievement and failure; every task and challenge, he turned it into a formation experience!