Source: http://vox.com/2014/11/20/7250255/im...

There are two big buckets of relief being granted here.

One is an expansion of a program Obama's already put into place: the 2012 Deferred Action for Childhood Arrivals program (DACA), which allows young unauthorized migrants who've come here as children (and who meet a few other requirements) to get temporary protection and work permits. 1.2 million immigrants are eligible for DACA already (although only about 600,000 have actually applied for and received protection).

The other is relief for parents of legal residents of the United States.

There are other small forms of relief that are helping some unauthorized immigrants — some of which we'll get to later.

The White House says that in total, nearly 5 million unauthorized immigrants will be protected from deportation. The two major deferred action programs cover about 4.3 million immigrants.