A passport is a document issued by the government of a country certifying an individual is a citizen of that country, About.com explains. Passports allow people to exit and enter their country of citizenship and travel to other countries.
Individuals applying for a U.S. passport should provide their birth certificate to certify their identity and citizenship, but there are alternatives for those who cannot provide a copy of their birth certificate. Applications for passports are available through the U.S. Department of State and many post office locations across the United States. There is a fee to apply for a passport, notes About.com.
If the applicant does not have his birth certificate, he can provide proof of his identity with a current, valid driver's license; a city, state or federal government ID card; a certificate of citizenship; or a military ID card. Applicants must also have their photo taken. The applicant's Social Security number is also necessary at the time of application. Applicants should check the status of their application approximately one week after they apply, advises About.com.
If an applicant is unsure of his eligibility for a passport, he can use the eligibility tool located on the Department of State website, Travel.State.gov, suggests the Department of State. The website has further information regarding the application process, fees and other requirements.