Liberation means the setting free of someone or something. Wild animals raised in captivity are often unprepared for their liberation when they are released back into the wild.
You'll notice right off the bat that liberation is related to the noun liberty — as in "liberty and justice for all." The difference is that liberation refers specifically to the act of being made free, of going from having no freedom to having it. Famous moments of liberation include Europe's liberation from the Nazis, the slaves' liberation from slavery in the U.S., and South Africa's liberation from the oppression of apartheid.