All of the answers above are correct. Another observation is that it is common usage to say that people* outlive other people, and that things** outlast other things. * or other living beings. ** or phenomena (such as dynasties or empires, for example). But yes, they are close synonyms.

Technically outlive refers to living things, humans and animals living longer than other people or animals. as all the examples above show. Outlast refers to things lasting longer than other things, However you will often hear outlived used for things too, I have also heard people use survived longer about things sometimes. I don't think its so common to say someone outlasted someone in the terms of a lifespan. Everyone uses them differently.

Everyone above is correct, but I want to give some sentence examples to show the distinct difference. "My friend died many years ago. I have outlived him." (Lived longer) "My friend and I held our breath for a long time, but I outlasted him."

If you outlive someone you outlast them, but outlasting them in a marathon run does not mean you will outlive them. :P

to outlive means to live longer than someone. For example: to outlive an enemy to outlast means to last longer in a certain struggle. For example: warm-blooded animal creatures outlasted the dinosaurs.