The immigration plans blocked Thursday by the U.S. Supreme Court are known as Deferred Action of Parents of Americans and Lawful Permanent Residents, or DAPA, and Deferred Action for Childhood Arrivals, or DACA.
DAPA was introduced by the Obama administration in November 2014.
It grants deferred action status to some undocumented immigrants who have lived in the U.S. since 2010 and have children who are either American citizens or lawful permanent residents of the United States.
Those immigrants must have been in the United States since November 2014 without holding lawful immigration status.
They must not have been convicted of a felony or significant misdemeanor and must not otherwise pose a threat to national security.
The "deferred action" does not equal full legal status, but instead confers exemption from deportation and a 3-year, renewable work permit.
DACA was introduced by the Obama administration in June 2012.
It originally allowed some illegal and undocumented immigrants who entered the country before their 16th birthday and before June 2007 to get exemption from deportation and a renewable 2-year work permit.
Eligible persons must have lived continuously in the United States since 2007.
They must be enrolled in school, have completed high school or the equivalent, or have been honorably discharged from the armed services or Coast Guard.
They must not have been convicted of a felony or a serious misdemeanor, or otherwise pose a threat to national security.
In November 2014, DACA was expanded to include illegal immigrants who entered the country before 2010, and it eliminated the requirement that applicants be younger than 31 years old.
New applications to DAPA and DACA are suspended until the legal stalemate is broken.