How to create a face inside a face in Blender?

Question

3D

How can I create a face in blender only in one selected face (see picture)

And how can I delete, for example, only a part of a previously created face without changing the model? (remove this edge in the picture)

Thanks in advance)

Answer 1

You can create a face on the face using the knife tool (hot key k)
Delete something without changing the rest - dissolve.