Summary: Oliver is so angry with Orlando that Orlando feels he'd better get out of there. Rosalind and Celia buy a flock of sheep and dress up like shepherds; they call themselves "Ganymede" and "Aliena." Orlando, who is now without any way to support himself, rushes with his sword after the followers of the banished Duke. Orlando demands that they give him food; he is surprisingly welcomed to join the band of foresters, who spend their time hunting and singing. The Duke has been transformed into a sweet, gentle and quiet person. His followers have also been transformed (save Jacques) who now profess that they "have no enemy but winter and rough weather" (2.5.7). The forest is now full of people pretending: pretend shepherds and pretend foresters.
If you are looking for some key lines that show character and conflict between Rosalind and Orlando, the first sixty lines of this scene show Rosalind's wit and Orlando's virtue (and gentle humor). For example, 5.2.14-22:
O, my dear Orlando, how it grieves me to
wear thy heart in a scarf!
It is my arm.
I thought thy heart had been wounded with the claws
of a lion.
Wounded it is, but with the eyes of a lady.