Baggage check or airport check-in is a service offered by commercial airlines. Before passengers board their plane, they turn over their luggage to the airline; they are then to be united with their items at the destination. 

Airlines always enforce limits to carry-on bags. Baggage that exceeds these limits are not allowed into the aircraft's main cabin and need to be checked in. This allows sufficient space in the cabin as well as quicker boarding and disembarkation. For the passenger, this permits ease and mobility. 
 

Checked luggage has a size and weight limit, and all excess requires a fee. Checked baggage restrictions vary from airline to airline, so it's important to find out about airline luggage rules and baggage fees before you begin packing. Details can often be found on your itinerary, or on the airline's website. Contact the airline if you have any questions.
 

Checking Your Baggage
 

This is usually the first procedure passengers do at the airport when going on a flight. At the check-in desk, an airline agent first inspects tickets, passports (including visas, if required) and other documents. The passenger then turns over the luggage for checking. All baggage is weighed, inspected, and tagged by the airline agent. If there are any baggage fees, this is the time to pay them. 
 

You would also be asked to fill a form; this will be helpful in case your bags are misplaced, so be sure to give correct information.
 

Most airlines offer online checking to hasten the process. It lessens your time at the counter and eases traffic.
 

What Happens to Baggage Upon Checking
 

After your baggage has been checked and tagged, it's transported by conveyor belt into the baggage system. Out of sight, it's scanned by the Transportation Security Administration (TSA) to see if there are any prohibited items. If anything seems questionable, a TSA agent will have to force your bag open for a search. If all is well, the luggage is prepared for loading.
 

The tags (those attached by airline agents at the counter) are important in making sure the luggage are loaded in the proper flight. Modern airports have scanners that sort the tags and direct them to the appropriate gate. Other airports do this manually. Once it reaches the proper gate, your baggage is then loaded into the aircraft. It joins you in your flight, but it remains in the cargo area.
 

At the destination, airline personnel unload the cargo once passengers disembark. The bags are then taken to a conveyor belt in an area of the airport inaccessible to passengers. From there, they are transported to the carousel in the baggage claim area. You will then have to simply wait for your luggage to pass by so you could pick it up.
 

Tips for Checking Baggage
 

- Excess baggage requires a fee, so it is best to pack light. 
- Know the allowances and prohibitions, and follow them. Checked baggage restrictions vary, so be sure to get the correct information from your airline. Contact them if anything is unclear.
- Take laptops, cameras, and other sensitive items in your carry-on; never check them in. Security scanners may be harmful to these devices. Do the same with medicine, prescriptions and personal medical supplies.
- Be sure to put tags on all your luggage, including carry-on bags and laptops. 
- Buy sturdy, waterproof bag tags, preferably ones with opaque covers to avoid displaying your identity to strangers. 
- Make sure to place your name, address and telephone number on each tag. 
- Don't forget to secure all your bags with a padlock. Choose locks approved by the TSA, so TSA agents won't have to destroy your lock in case they need to search your bag.
- To make it easier for you to identify your bag at the baggage claim carousel, you may want to fasten a bright-colored ribbon or tape.