classification of securities

there are three classification of marketable securities. the names and a brief description follow.
TRADING Securities bought and held principally for the purposes of selling them in the near term with the objective of generating profits from short-term price changes.
Available-for-sale Securities not classified as either trading or held-to-maturity.
Held-to-maturity Securities that are held with the intent to hold to maturity. Only debt can be classified as held-to-maturity.