Interstellar ending explained

What happens

Cooper falls into the black hole and finds a space behind Murph's bookshelf where time is a place. He realises he was the ghost all along and sends her the data through gravity. She solves it, humanity escapes, and he wakes near Saturn.

The last image

Cooper, reunited with his elderly daughter, sets off in a ship to find Amelia, alone on the third planet.

What it says

Love is the force that crosses distance, and here it works as information. The film ends on reunion and a new journey because its question was never only whether humanity survives, but what we would give up for the people we cannot reach.