Can someone pls explain nominalization of adjective and verbs

Nominalization is the transformation of adverbs, adjectives or other parts of speech into nouns. We can form nominalization by adding suffixes to adjectives or verbs. A nominalized adjective is an adjective that has undergone nominalization, and is thus used as a noun. For example, in the rich and the poor, the adjectives rich and poor function as nouns denoting people who are rich and poor respectively.