The rising sign is the sign that was rising on the east horizon during the time and at the place of your birth.
This means that it is the sign in your first house in the natal chart.
The theme of the first house could be described as "me against the world".
Its your physical self, your body in the physical world around you.
Its ruled by Aries and Mars, all about independence and fighting and proving yourself in front of the world.
Its about you as an ego being seperate from the world and the people around you.
One could describe your rising sign as your "self image" rather than your "public image".
It is the way you see yourself, which is not necessarily the same way other people see you.
It is the role you think you have to fulfill to fit into this world and the kind of person you think you have to live up to being.
Of course, if you're doing a good job at living up to this role you see yourself in, others will probably also have this impression of you but this is not always the case!
Being aware of the self image you've set for yourself helps you get rid of these limiting expectations.
How do you feel about your rising sign?