Why are D-Block elements called transition elements?

why are D-Block elements called transition elements?

The position of d-block elements is in between the s-block and p-block elements in the periodic table. These d-block elements are called transition elements because they exhibit transitional behaviour between s-block and p-block elements.

Their properties are transitional between highly reactive metallic elements of s-block which are typically ionic compounds and the elements of p-block which are largely covalent.