My wife has ovarian cancer. (ELI5)

Found out not two hours ago that my wife has Ovarian cancer and I need a few things explained to me. I was not there, so I have a very limited bit of information.

Can someone explain a "75% 5 year survival"? Is she looking at 5 years or less to live?

Is there anything I need to know that will help me help her?

I'm sure there will be more questions once I have a chance to think straight.

Thank you in advance for any assistance.