At its annual keynote, Apple announced that iPhone 7 honors the IP67 protection standard. In layman's terms, the iPhone 7 and iPhone 7 Plus are both water and dust resistant.
Let's remember that water resistant DOES NOT mean waterproof in any way shape or form. Water resistant means that the phone will not get damage from some water splashing on it.
No, do not submerge your phone in the pool and do not drop it in the toilet, damage can still occur. However, the iPhone 7 should be able to survive a coffee spill or some back splash from the shower.
The iPhone 7 and iPhone 7 Plus will be available for pre-order on September 9, with shipping beginning September 16.