The ISOFIX system is a method of securing car seats to the vehicle using anchors instead of seatbelts. This makes it easier to install the seat correctly, and it also helps to keep the seat more securely in place during a collision. Not all cars are compatible with ISOFIX, so you'll need to check your vehicle's owner's manual to see if it's an option for you. If your car doesn't have ISOFIX, you can still use a seatbelt to secure the car seat. Keep in mind that even if your car has ISOFIX, you'll still need to use the seatbelt or LATCH system to properly secure the seat. The ISOFIX anchors are just an additional measure to help keep the seat in place.