noun
indentation
in-den-TAY-shuhn/ˌɪndenˈteɪʃn/
An inward recess from the surrounding edge.
The rectangular notch forms an indentation in the wooden block's edge.

Etymology
A notch in an edge continues the “tooth” image of indent; a hollow made by pressure comes from a separate indent meaning “press in.” The supplied sense covers both histories.
In context
indentation is actually a small space that is created from the left side of the margin
More examples
- Each paragraph begins with an indentation of half an inch.
- The heavy chair leaves small indentations in the soft floor.
- An indentation along the lid's edge gives your fingers a grip.
Forms
indentation · indentations
indent verb — To set inward or make a recess.