As your child grows, there are technically four stages of car seats that should be used to keep them safe in a vehicle. After birth, a child is considered to be in the first stage. Most car seats will have an infant insert that comes with the car seat (thus, making it an infant car seat). This is to be used until your child outgrows the insert, at which time they would sit properly in the car seat. During the infant stage, the car seat sits facing the seat back behind it. This ensures optimum safety for the child, as standard airbags can harm children while they’re young. There are some carriers and seats available that are rear-facing only, but often, it will be more economical to buy a two-stage seat which supports both forward facing and rear-facing configurations. Seats that are exclusively rear-facing are typically only designed to last through the infant stage. You could call these a pure infant car seat. Typically, this will last until one of the following happens: the child grows too tall for the infant car seat, the child exceeds forty pounds, or the child reaches two years of age. Some car seats are designed to extend the amount of time the child can sit rear-facing. The second stage in a convertible car seat is the forward facing stage. This stage will typically last until the child exceeds sixty-five pounds. Some car seats can be used even longer, such as the Maxi-Cosi Pria 85 Max, which can be used in front position until the child weighs eighty-five pounds. In the front stage, the child still uses the included harness with the seat, but sits facing forward normally. The third stage in a convertible car seat is the backed booster stage. During this stage, the child still sits in the car seat as usual, but instead of using the straps on the car seat, they sit buckled into the car’s seat belt. This setting can typically be used until the child reaches one hundred pounds. The fourth and final stage of car seat use is the backless booster stage. During this stage, the back is removed from the car seat (or a standalone booster seat can be purchased), and the child sits atop the booster, but with their back against the car seat. These seats use standard seat belts, and the extra height provided by the booster seat helps the child sit within safe range of the belts. The backless booster configuration can be used until the child reaches 120 pounds. However, many children will be old enough to sit without a booster seat before reaching that point.