Enterprise installation done at server side and you will be able to connect to enterprise manager page on server side and client side using IP or hostname for server , if you want to connect on client side you should add Server ip on hosts file .
What is ur db version.
From 10g you can have EM configured on the server and you can access the EM DB console page through a browser on the network from any connected client.
In 9i the GUI based EM could be installed in client machine aswell to connect and manage multiple database instances. Moreover you can still use the old 9i GUI based enterprise manager and connect to 10g/11g database instances.
I see that this is your first post so I recommend you to start using the latest and the best Oracle 11g Database.