Transition elements (also known as transition metals) are elements that have partially filled d orbitals.
IUPAC defines transition elements as an element having a d subshell that is partially filled with electrons, or an element that has the ability to form stable cations with an incompletely filled d orbital.
Titanium and iron are the most abundant transition elements.
These metals are versatile in use like iron is used in manufacturing and construction, and titanium is used in the medical field for artificial hip replacements.