-Quadratic Edge is not a straight but a broken line and can be defined
-by three points: first, middle and last. All more complex \b Quadratic
-\b Elements differ from ordinary ones in that they consist of Quadratic
-Edges.
+Quadratic elements are defined by the same corner nodes as the
+corresponding linear ones, but in addition they have \a midside nodes
+located between the corner nodes on element sides.
+
+If a quadratic 2D element has an additional node at the
+element center, it is a bi-quadratic element (both TRIA7 and
+QUAD9 elements are supported). If a quadratic hexahedral element has 7
+additional nodes: at the element center and at the center of each
+side, it is a tri-quadratic element (or HEXA27).
+
+The convention of nodal connectivity of elements used in SALOME is
+the MED library convention. You can consult the description of nodal
+connectivity of elements in the documentation on MED library or
+\ref connectivity_page "here".
+
+There are several ways to create quadratic elements in your mesh:
+- manually (this way is described below);
+- use \ref quadratic_mesh_anchor "Quadratic Mesh" hypothesis to
+generate a quadratic mesh on your geometry;
+- convert an existing linear mesh to a quadratic one
+(see \ref convert_to_from_quadratic_mesh_page).