It's small enough to fit in a pocket, but is full of information, what is it? A passport card! Part of becoming an informed world traveler is understanding the anatomy of this all-important document. Most of the important information is found near the front data page that has your photo. As you embark on international travel, the other pages in this travel document will fill up with stamps that customs agents use to mark your entry. Each country issues its own passport, but the standard U.S. passport is always the same.

Page One: Message From the Secretary of State

The first page of a standard American passport includes a quote by Abraham Lincoln, an image of the seal of the United States, and a message from the office of the Secretary of State asking authorities of other nations to allow the passport holder access. The message is repeated in French and Spanish. This isn't a page that you'll need to use or refer to at any point during your travels.

Page Two and Three: The Important Information

Flip the first page to reach the most critical part of a passport: the photo page. In your own passport, on this page, you'll see your passport photo, a heading that reads "United States of America" and several lines of typed information. At the top, a letter designates what type of passport it is; most people have a standard type P version. Next to that is a country code (USA, in this case) and the passport's unique document number. If you hated your driver’s license photo, this is the perfect opportunity to take a better photo.

Below that are lines for the holder's last name, first and middle name, nationality, date of birth, place of birth, the date the passport was issued, the date it expires, the holder's gender, and the authority that issued the passport – the United States of America.

That's all information that the Department of State gathered from your application and the supporting documentation you provided along with the application. Page two is one of only two places in your passport where you'll see printed information specific to you; the other is the inside back cover, where the passport number is printed. All other pages should look the same as those of any other standard American passport.

Page three displays the preamble of the Constitution and has a line for the signature of the passport holder. Sign that line if you haven't already. Before approaching a customs agent, open the passport to this page to make the agent's job a little easier.

Pages Four Through 28: Everything Else

The fourth page of a passport provides lines for the holder to write in an address and phone number in the event that the document is lost, followed by three pages of general information about how to care for a passport and stay safe abroad. Once obtained, your U.S. passport book becomes one of the most important documents you will own. In times of need, it can even serve as proof of identity and U.S. citizenship when you don’t have access to a birth certificate or other identification.

Pages eight through 27, called visa pages, are mostly empty except for quotes from important American figures. When you arrive at customs of a foreign country, an agent will check the photo page to make sure it's valid and belongs to you, then flip to a visa page and press down a stamp that denotes the country and the date of entry. Some countries also use exit stamps to mark your departure.

Check the passport requirements for every country on your itinerary, especially if these pages are mostly filled up. Customs agents in some countries will stamp a page that's already half full. In other places, the requirements are stricter. To visit South Africa, for example, your passport must have two consecutive blank visa pages.

Important Tips

The most common mistake people make when applying for an official passport is that they do not leave room for the processing time that occurs after your submit your application. Sometimes it can take up to six months to actually receive the physical copy of your passport, so be sure to apply for one way in advance of any international travel. Your passport application will be accompanied by a passport fee as well, so show up with that fee in hand when you arrive to ship off your application.

Even if you do not anticipate traveling outside of the country anytime soon, it’s still a good idea to apply for a valid passport at the age of 18. Having a U.S. passport book ensures that you are ready to go in case you plan a last minute trip abroad. Passports do expire of course so keep an eye on your issuance and expiration date and be sure to apply for a new passport at that time, or if you undergo a name change.

To find out more about obtaining a U.S. passport card, visit travel.gov’s webpage.