You might want to specify what Oracle product you are talking about, since the first thing that comes to mind when you read “Oracle” is the database, but they in fact have many more products (more than 20 I think); and you are probably referring to Oracle Applications.
Take a look at thes articles on SearchOracle.com:
Oracle vs. SAP
Oracle vs. SAP: Round two
I’m using Oracle 11g.
And can you explain me in brief about SAP?
SAP has a ton of modules. You can read up on what some of there do here.
Oh Thanks for your useful link.