What chemical bonds are called covalent?

Covalent bond (atomic bond, homeopolar bond) is a chemical bond formed by overlapping (socializing) a pair of valence electron clouds. Connecting electronic clouds (electrons) are called a common electron pair.
The characteristic properties of the covalent bond — directivity, saturation, polarity, polarizability — determine the chemical and physical properties of the compounds.
The orientation of the bond is due to the molecular structure of the substance and the geometric shape of their molecule. The angles between two bonds are called valence.
Saturation – the ability of atoms to form a limited number of covalent bonds. The number of bonds formed by an atom is limited by the number of its outer atomic orbitals.
The bond polarity is due to the uneven distribution of electron density due to differences in the electronegativity of atoms. On this basis, covalent bonds are subdivided into nonpolar and polar.
The polarizability of the bond is expressed in the displacement of the bond electrons under the influence of an external electric field, including another reacting particle. The polarizability is determined by the mobility of electrons. The polarity and polarizability of covalent bonds determines the reactivity of molecules with respect to polar reagents.
Electrons are more mobile, the farther they are from the nuclei.