The first six months of life the child usually sleeps on a walk, so it is suitable for a stroller, a cradle, in which it is convenient to lie. But after 6-8 months, when the child has already strengthened his spine, and he confidently sits, you can go on a stroller. It is actively used usually up to 2-3 years.
You can buy two strollers: a cradle for the first six months and a stroll for later. And you can choose one stroller “2 in 1” and even “3 in 1”. Such sets includes: in the first version: chassis and two bodies, and in the second – also a car seat.