Anterior pituitary gland secretes growth hormone while posterior pituitary gland secretes vasopressin as well as oxytocin hormone.Anterior pituitary gland is quite bigger as compared to the posterior pituitary gland.Anterior pituitary gland is located on the front side of the pituitary gland while posterior piuitary is located at the back.Hope i helped u:)
Anterior pituitary make hormones by itself,but their secretion is controlled by hypothalamus. Anterior pituitary hormones are proteins and glycoproteins, including growth hormone,prolactin, and glycoprotein hormones. It consists of a collection of cell types, each of which  release specific hormones into the systemic circulation.
Posterior pituitary lies beneath the hypothalamus, and it is connected through the pituitary stalk to the hypothalamus.It secretes posterior hormones made up of glial tissue and axonal termini. It basically stores hormones, which are synthesized in the cell bodies in the hypothalamus. It does not produce its own hormones unlike the anterior pituitary does.