Picking a suitable car seat for your infants can be a challenging task, particularly when you're shopping for a convertible car seat. You need to do a lot of in-depth research to make an informed decision before settling on one. t's a portable seat used by small children or infants; it's usually attached to the car seat and safely holds the kid. Typically, the seats can be used in rear-facing or forward-facing positions, depending on your infant's height and weight.