opening Oracle in web browser, I am assuming you mean how to access Enterprise
Manager via the browser which can be done using this URL construct – http://hostname:portnumber/em where
host name is the name of the computer where you installed Oracle and port 5500
by default. Useful documentation can be found at http://docs.oracle.com/cd/B13789_01/server.101/b10742/em_manage.htm
The Max memory depends on the operating system type and version, but Oracle can
scale to the Max of the machine and operating system. The IP address is the
address of the machine you installed the Oracle server software on. I hope that
this information helps.