U.S. Green Card:

1. A U.S. Green Card, also known as a Permanent Resident Card, is an immigration document that allows a foreign national to live and work permanently in the United States.
2. It is proof of legal permanent residency in the U.S.
3. It is issued by the U.S. Citizenship and Immigration Services (USCIS).

Green Card Features:

1. The Green Card allows its holder to live and work indefinitely in the United States.
2. It provides the opportunity to apply for U.S. citizenship after meeting certain eligibility requirements.
3. It grants certain rights and benefits, such as the ability to sponsor family members for immigration and to travel outside of the U.S. and return without a visa.
4. It also comes with certain responsibilities, such as paying taxes and obeying U.S. laws.

Detecting a Fake Green Card:

1. Look for spelling or grammatical errors on the card.
2. Check the card's hologram to see if it changes color when viewed from different angles.
3. Examine the font on the card to see if it matches the official font used by USCIS.
4. Look for a raised USCIS seal on the front of the card.

Waiting Period for Different Groups:

1. Immediate relatives of U.S. citizens: No waiting period, as visas are immediately available.
2. Family preference categories: The waiting period can range from several months to several years, depending on the relationship to the U.S. citizen or permanent resident sponsor and the demand for visas.
3. Employment-based categories: The waiting period can also range from several months to several years, depending on the specific employment category and the demand for visas.
4. The waiting period can also be affected by USCIS processing times, background checks, and any delays or requests for additional information during the application process.