What is a personal item bag?
Most airlines these days allow passengers to bring two things onto the plane with them: a carry-on, which goes in the overhead compartment, and a personal item bag, which goes under the seat in front of you. The difference between the two basically boils down to size, since the personal item needs to be small enough to fit under the seat.
Why do you need a personal item bag for travel?
1) Because a personal item is more convenient than a larger carry-on.
If you only bring a carry-on bag that has to go in the overhead compartment, it’ll be much more difficult to get to during your flight. You’d have to stand up in the aisle, struggle with lifting a heavy bag overhead, and risk things falling out onto your head if the plane hits a bump. Plus it’s not allowed near the beginning and end of the flight or if there’s turbulence. Depending on when you board, you may not even be able to store that bag in a compartment near your seat. Being able to grab things from below the seat in front of you is much easier and can be done at any time during the flight (except takeoff and landing!), and without any glares from the flight attendants.
2) Because a personal item can double as something else you’ll need during your trip.
As long as your bag is small enough to fit under the seat in front of you, it can be a personal item. That means purses, shoulder bags, briefcases, laptop cases,shoulder bags, small backpacks, and duffel bags can all work as personal items, and you may need them during your trip anyway. Choose a personal item that matches your travel style and other needs, and you’ll get way more use out of it.