Do you understand the basics of air travel and luggage restrictions? There have been various changes throughout the years due to increase security at airports. You'll need to understand the luggage restrictions.

Do note that there may be differences in restrictions when traveling outside of the United States. Be sure to check with the airlines about any additional restrictions if you are traveling to other countries. Here's a quick guide to what you can and cannot bring with you on the plane.

Liquids, Gels, Aerosol Containers

The basic restriction is that you must have only 3 ounces of each liquid in small containers. You can't have 3 ounces of liquid in bigger containers. That means you have to leave your rolled up toothpaste and big bottles at home.

On top of that, you have to put all of your liquid small bottles in a quart size only plastic baggie. That quart sized plastic bag must have a zipped top. You can't use gallon-sized bags, and you can't use bags that are unzipped, like a sandwich bag.

Once you get to the airport, you have to pull out this bag and put it on the conveyor belt if you are taking it with your carry-on luggage.

Save The Trouble Tip - Don't bring anything liquid or gel with you if you can help it. Buy new small travel size items when you get to your destination, and throw them away before you take off for home.

Exceptions To The Rule - Baby formula or milk for baby, or juices for toddlers. Prescription or over the counter products, including eye saline. Juice or liquids for people with a medical condition. Basically, if you have any medical condition or disability and you are taking liquids with you, you can bring those items with you on the plane, you just need to declare it to the security personnel at the airport.

Food and Drinks

Like the rules above, if it's a liquid, or somewhat liquid, it has to be less than 3 ounces. You can have them checked or in your carry on items. In most cases any food that you have, as long as it is packaged properly, can be taken with you.

However, items you buy at the airport can be taken with you on the plane. If you're at the airport and buy something for the trip, you can save some checkpoint hassle by purchasing food and drinks beyond the security point.

Save The Trouble Tip - Use clear packaging when you take food items from home with you, that way security won't have to open things up to see what is inside.

Cigarette Lighters And Matches

Your common every day lighter is permitted in your carry-on luggage only. You might have to throw away some if you have more than one on your person.

You can also take with you matches, but they must not be the strike anywhere kind. They must be in a small pack.

Electronic Items

In general, all electronic items such as PDAs, cell phones, laptops, computer equipment, pagers and the like are permitted both checked and in your carry-on luggage. Most likely you'll have to be prepared to pull it out and place it in special bins when going through the X-ray machine.

For cameras, if you have undeveloped film, the X-ray machine will destroy this, so you should simply declare what you have to the security people and ask them to do a hand search of these items.

Sharp Objects

There are many restrictions regarding sharp objects. The general rule is if the item is longer than 6 inches and sharp, check it with your luggage, don't take it with you in your carry on luggage.

Anything less than 6 inches, not a knife, and usually meant for personal use like knitting needles or a nail file. You cannot bring a knife with you on the plane, even a small pocketknife. Put these with your checked baggage.

Tools in general can be checked, though items less than 6 inches are allowed on carry-on luggage. Larger tools, especially sharp objects, must be checked.

Save The Trouble Tip - Do you really need any sharp metal item while in flight? Keep it all with your checked luggage.

Sporting Goods, Martial Arts Items and Firearms

To keep it simple, most sporting goods aren't allowed as carry on, and must be checked. Same thing with the martial arts items, you will have to put these with your checked baggage. Again, the same rule applies for firearms. Guns and knives can be brought with you, but must be checked baggage. You can also bring ammunition, but again, it must be a checked item. It is recommended that you declare what you have to the individual doing the inspection.

This also applies to anything that looks like a gun, including a BB gun, or pellet gun or any other sort. You must check these items as baggage. The pellets and BBs must be checked as well. To be safe, check toy guns as well.

Things You Can Not Have With You

This is a list of items you cannot have with you, either checked or as a carry on item. You cannot bring these items on the plane with you under any circumstances. You could face severe penalties if you bring these with you.

Flares

Gun powder

Blasting Caps

Dynamite

Fireworks

Hand Grenades

Plastic Explosives

Aerosols *except for toiletry items

Fuel

Gasoline

Gas Torches

Lighter Fluid

Torch Lighters

Strike Anywhere Matches

Flammable Paints

Turpentine and Paint Thinner

Chlorine for Pools and Spas

Fire extinguishers

Liquid Bleach

Spillable Batteries *except for wheelchairs

Spray Paint

Tear Gas

Note: You cannot bring with you realistic replicas of these items either.

Save The Trouble Tip - If you must have these items, plan to buy one at the location you are traveling to, or ship it to yourself. (Make sure you check regulations for shipping these items.)

These restrictions are in place to help keep you safe while flying. Planning ahead is the best way to prepare and make sure what you need makes it through to your destination. The general travel tip: Less is better. Buy items when you get to the location. In most cases if you do need to bring it, try to put it in your checked baggage.