Infant car seats install rear-facing only, and are best for babies up to a year old and weighing between 4 and 40 pounds. This type of car seat is the best first seat for most babies and the best fit for newborns. Plus the convenient carrier makes it easier to transport a small baby.

All-in-one car seats are designed to accommodate kids from birth to booster age: Rear-facing for newborns to 2 years old (weighing 5 to 45 pounds), and forward-facing for kids that weigh 20 to 65 pounds. The booster mode of an all-in-one car seat can be used for kids weighing 30 to 120 pounds.

Booster seats position a child that weighs 30 to 120 pounds so that the vehicle seat belt lays across their body correctly. This is the last seat after a child outgrows a forward-facing harnessed car seat and before using only a seat belt.