With green cards people are allowed to stay in the USA for a longer time and work there
. These United States Permanent Resident Cards were usually given to people of some categories, which have exceptionally talents or special scientific knowledge. Also people who work for church or who are parents, children or sister and brother from an American can get green cards. Next to these there is the chance in the green card lottery in USA. This lottery exists since 1987 and was the idea of the president Ronald Reagan. He saw, that there were too much emigrants from some countries and so the Diversity of people was in danger. For more Diversity the green card lottery is open for countries with a low emigration rate. People who want to get a green card don't have to pay money at first, but for a medical check up and the bureaucracy people have to pay some hundred dollars. The participation at the lottery is online, so that everyone with internet can get a green card. If they've won at the green card lottery they have to qualify for the necessary Visa. Therefore some Criteria might be important. First the Emigrants have to show they are qualified in a profession with some years of experience or that they completed the minimum schooldays. Next they have to submit a police clearance and an attest of the medical examination. Also they should have some money and a Job Offer to start in the USA successfully. At least the candidates get a date to speak with the American embassy. Is it successfully they get a Visa to immigrate to the states and have to go there within six month otherwise the Visa forfeits.