William Shakespeare's As You Like It is a very witty comedy. Here, the characters of Orlando and Oliver are clearly distinguishable from each other.
Oliver is Orlando's elder brother. Both are the sons of late Sir Rowland de Bois. In the very beginning, we find out, in accordance with the rule of primogeniture in England, which instructs that all the property would be inherited by the eldest of the family, Orlando gets the possession of the belongings that his father leaves. Though, he was instructed to take proper care of Orlando, he, out of jealousy and loath, makes Orlando totally deprived. In fact, when the royal wrestler Charles is supposed to fight Orlando, Oliver leaps with joy thinking of the probable death of his brother. But, in Orlando, we find no such cruel feeling or motive. He is not even confident enough to stand on his own feet. He just flees away in fear of his brother.
Later in the play, when Oliver is attacked by a lioness in the forest of Arden, it is Orlando who rescues him. Orlando could have shown abhorrence or reacted vindictively by not saving Oliver, but he does not do so. Unlike Oliver, he proves to be a sensible brother and a good-natured human. And, at this point, his valour is also expressed.
Another notable point is that, Orlando's character develops gradually with the help of Ganymede, whereas Oliver's character faces a sudden change in the forest of Arden which is very miraculous.
Finally , the difference between the two brothers has clearly been depicted in the play, where Shakespeare's portrayal of Orlando is almost a mirror image of Oliver.
The first time we meet Orlando, he's fired up and says he's ready to "mutiny" (1.1.1) against his big bro. What's Orlando so angry about, you ask? Well, his father has died and he's been left penniless because of the system of primogeniture, which says that oldest sons get to inherit all of their fathers' wealth while younger sons, like Orlando, get zilch. Wait – it gets worse. Not only did Orlando get shafted in his dad's will, he is also treated like dirt by his older brother, Oliver, who is supposed to be taking care of him:
My father charged you in his will to give me good
education: you have trained me like a peasant,
obscuring and hiding from me all gentleman-like
qualities. The spirit of my father grows strong in
me, and I will no longer endure it: (1.1.10)
Orlando knows he's angry, but here, he doesn't know quite know what to do about it so he vents his frustration by running out and challenging Charles, the court wrestler, to a match. Orlando is the underdog every audience roots for, and miraculously he wins the match, even though Charles has a reputation as a bone crusher.
Oliver is Orlando's older brother, and being the oldest son of their father, Sir Rowland de Boys, through the practice of primogeniture, he has inherited all of his father's property.
At the top of the play we see Orlando railing against his situation. He sits around at home and does nothing because his brother refuses to send him to school. Orlando, frustrated by his situation decides to confront his brother. In his confrontation he demands his inheritance so that he can be the master of his own fate, his brother denies him.
After the brothers' brief altercation, Charles, the Duke's wrestler, visits Oliver. Charles makes Oliver privy to a rumor that he has heard, that Orlando is going to challenge him. Charles, being a friend to Oliver is hesitant to harm Orlando. Oliver tells Charles that his brother is a villain and that he will cheat using dastardly means to ensure his victory; and that Charles should do whatever he can to win.
In the first two acts of the play, Oliver sees Orlando as a pest and a threat. Oliver wants Orlando out of the picture, presumably so that he can keep all of his late father's property. Orlando, penniless and powerless flees to the forest when his servant, Adam, warns him of his brother's treachery.