Peace Lilies are not lilies. They are aroids, related to Monstera and Philodendron, and the white flower is actually a modified leaf called a spathe wrapped around a spike of tiny real flowers.
They are among the few houseplants that will flower reliably in an ordinary living room.
What every Peace Lily wants
Medium to low light, which is unusual for a flowering plant. Direct sun scorches the leaves.
The famous trait is the wilting. A thirsty Peace Lily collapses dramatically, leaves hanging over the edge of the pot, and then recovers completely within a few hours of watering. It is alarming the first time and entirely normal.
Do not use it as your watering schedule though. Repeated collapse weakens the plant over time.