Specific terms are unknown, but it states that New Genesis and Apokolips were not to interfere with each other's affairs. To seal the pact, Highfather, ruler of New Genesis, and Darkseid, dreaded lord of Apokolips, exchanged their infant sons. Highfather gave his son, Scott, to Darkseid, who in turn gave his son, Orion, to Highfather. In the end, Highfather would temper Orion's aggression, while Scott would reject the influences of Darkseid and Granny Goodness, and escape, returning to New Genesis with his future wife, Big Barda.
Highfather would attempt to thwart Darkseid's plans as much as possible without breaking the Pact by placing worlds like Earth under his protection, which would make an attack on such worlds a violation of the Pact.
Darkseid merely interpreted the pact as an armistice, and sought the Anti-Life Equation to conquer New Genesis and the universe.
After Darkseid was resurrected by Lex Luthor (and Tala), he announced his intention to attack New Genesis after conquering Earth (not caring about the Pact anymore). This did not happen as he vanished while attacking Earth. As such, the state of the treaty is unknown.
In the DC comics, Highfather formulated the Pact as a means to redeem Orion and test Scott Free's compassion. The Pact succeeded in both, but it also clouded relations between Scott and Highfather.
The Pact also specified that it was in force as long as Scott and Orion were on Apokolips and New Genesis, respectively, meaning that when Scott escaped Apokolips, the Pact became null and void. This particular aspect of the treaty does not appear to be part of the DCAU, as Highfather and Darkseid both appeared to hold the Pact still in force as of Darkseid's first invasion of Earth.