Levi's title, Survival in Auschwitz, is direct: it sums up, without frills, what this book is all about. (In fact, when the book was published n the U.S., the title was changed from the original If this is a man because the publishers thought this would make the book's subject clearer to potential readers.)
What "survival" means, though, is not quite as clear-cut. It refers to the standard dictionary definition of being able to overcome adversity in order to remain breathing. But "survival" also suggests all of the ways the prisoners had to bend their ethics and morals in order to make it out alive. Along the way, some prisoners (through no fault of their own) lose part of what it means to be human.
It's this human element, Levi implies over and over in the book, that moves man from just "surviving" to "living"—which was impossible in Auschwitz. Only basic survival was possible.