Most of the Iterators and Iterables methods are LAZY! What does this mean

1 of the presentation says "These methods are LAZY!"

Iterable transform(Iterable, Function)*
Iterable filter(Iterable, Predicate)*
T find(Iterable<T>, Predicate)
Iterable concat(Iterable<Iterable>)
Iterable cycle(Iterable)
T getOnlyElement(Iterable<T>)
Iterable<T> reverse(List<T>)

Can someone help me understand what they mean by this, lets say I've a collection of Persons and I apply a filter to return only the persons whose last name is DOE.

So does this mean that the "filtering happens only on the first call to doeOnly.next()?"

List<Person> persons= ....
Iterable doeOnly= Iterables.filter(persons,DOE_AS_LAST_NAME_PREDICATE);