Annulus
Annulus
It is called leading.
parallel
What is it called to circle around a point in space
In 2-dimensional space, it is the difference between their y-coordinates, in 3-dimensional space, it is the difference between their z-coordinates.
Vertex
The half period zone is provided by an optical device known as Zone plate,The zone plate is so called because it is constructed following Fresnel zone law.It is simply a plane parallel glass plate having concentric circles of radii accurately proportional to the square roots of the consecutive natural numbers 1,2,3......etc. The even or odd order annular space between the circles are completely dark.
The space between your eyebrows is called the "Glabella."
The space between the vocal cords is called the glottis.
The space between letters in printing (or typography) is called tracking.
space, or outer space
It is called leading.
In typesetting the space between lines is called lead or leading. The space between letters is keening.
The space between the arachnoid and pia mater is called the subarachnoid space
It is called Negative Space.
Negative space
The space between the legs is called the pubic area. Other associated anatomical structures are the perineum and the anus.
That space is called as sub arachnoid space. It is filled with cerebrospinal fluid.