Cytoplasm is the ground substance present between plasma membrane and nucleus of all cells excepting viral cells. It is an amorphous, translucent, homogenous, colloidal substance, differentiated into cytoplasmic matrix and cytoplasmic structures. Cytoplasmic matrix, hyaloplasm, or cytosol is differentiated into peripheral denser and non-granular part called cortex or ectoplasm and inner less denser and granular part called medulla or endoplasm. It is a true solution of nucleotides, vitamins, RNAs, minerals, sugars, amino acids and colloidal solution of proteins. Cytoplasmic structures include cell organelles.