at the bottom - the lowest, furthest, or deepest part of something seen as the point in space
There's a label on the bottom of the mug. [outside]
There's some dirt at the bottom of my mug. [inside]
Please put your name at the bottom of each page.
She lives at the bottom of the street.
He was standing at the bottom of the hill when I first saw him.
in the bottom could mean that something is inside the bottom part (surface) of something.
Student or Learner