The program allowed illegal aliens who had come here as children to stay in the country.
Shortly after the November election in 2014, President Obama expanded DACA by adding DAPA, the Deferred Action for Parents of Americans and Lawful Residents. That program purported to create a pathway to citizenship for the illegal alien parents of American citizens or lawful residents.
A federal court stopped DAPA before it could be put in place and the Supreme Court allowed it to stay in place. As of now, DAPA has not been enacted due to court order. President Trump, in the last hour, announced he is withdrawing the DAPA memorandum, but will keep DACA in place.
Note, however, that the part of President Obama’s plan to expand DACA to three years instead of two has been withdrawn and DACA will again be a two year program.