Compare the characters of Orsino and Viola in Twelfth Night.

Orsinio, the Duke of Illyria, is an intense, emotional, and passionate man who is in love with the idea of love. A statement he makes early in the play characterizes him:

If music be the food of love, play on!

Orsinio loves sensual pleasures and is often overly emotional, sentimental, and bombastic—tending to use inflated or exaggerated language.
Viola, in contrast, is self-controlled and dignified. As a person shipwrecked in Illyria, she has to survive by her wits and does so by pretending to be a man. Witty and intelligent, she has to be careful about everything she does so as to not slip up. Despite her ruse, however, Viola's manners and personality are attractive to the duke.
Orsinio, as a duke, can indulge his emotions and temper; he expects others to cater to him and overlook his excesses because of his position of power. Viola, because of her relative powerlessness, must keep her emotions under control and be attuned to the moods of those who are higher ranking than her.
What they share, however, is love. Viola is in love with Orsinio, but because she is disguised as a man, can't show it, while Orsinio, though he doesn't know it, is in love with Viola. Viola's love is much more restrained and silent than Orsinio's sentimental outbursts, but it is still love. She explains (while pretending to speak of someone else):

She never told her love,But let concealment like a worm i' th' budFeed on her damask cheek. She pined in thought,And with a green and yellow melancholyShe sat like Patience on a monument,Smiling at grief. Was not this love indeed?