difference between fryer and boiler?

[Giddyup]

We're hoping to put any roos out of this batch in the freezer - but this would be our first time. They are a dual purpose bird (australorps).
What is the difference between a fryer and a boiler? just age? I imagine that with this breed we may have to wait longer to make dinner worthwhile - up to six months?
Is it worth trying to 'feed them up' or just let them be (ours free range).
Thanks!

 

[jaku]

Quote:
I've always heard it as a fryer/broiler is the same thing, and butchered at about six weeks, whereas a roaster is a couple of weeks older.