Deferred Action for Parents of Americans and Lawful Permanent Residents (DAPA) was a planned immigration policy giving deferred action status to people living in the United States since 2010 who have children who are US citizens or lawful Permanent Residents (parents of green card holding children). It was blocked in courts.
DAPA was introduced by the Obama administration in November 2014. DAPA was an attempted executive action by President Obama, not a law passed by Congress.
Immigrants provided temporary amnesty by DAPA must have been physically present in the United States since November 2014 without holding lawful immigration status, and must have been residing in the US since 2010. They must not have been convicted of a felony or significant misdemeanor and must not otherwise pose a threat to national security.
DAPA had first been attempted in Congress but fell apart at the last moment. President Obama vowed to implement DAPA through executive orders. The President's program, when combined with DACA, would have delayed deportation of slightly less than half of the 11 million undocumented aliens in the United States.
Twenty six states immediately sued to prevent the expansion, and a US district court ordered a preliminary injunction blocking DAPA. This blocked DAPA until the US Supreme Court heard the case. With one of the nine Supreme Court justices passed away and not yet replaced, a tie was possible and the court deadlocked 4-to-4 and the Supreme Court was able to make no definitive ruling, leaving the injunction in place. Their ruling read, in its entirety, only a single sentence, "The judgment is affirmed by an equally divided Court." Thus, DAPA remained not implemented.
The lack of a meaningful ruling means the court did not actually rule against DAPA - it could be attempted by executive order again. President Trump’s administration has no interest in implementing DAPA.