what is oracle universal installer in oracle database products I am new to oracle database products. I am planning to install oracle 11g express edition in my PC,it looks like a standard installer.But in many of the oracle database installation tutorial mentions oracle universal installer.oracle universal installer provides more open options,but those options and features not available in downloaded oracle 11g express edition.

difference between two https://docs.oracle.com/cd/E17781_01/install.112/e18803/toc.htm#XEINW151 and http://www.oracle.com/webfolder/technetwork/tutorials/obe/db/11g/r1/prod/install/dbinst/windbinst2.htm

so anyone explain me exactly what is oracle universal installer??Thx in advance.
Oracle's installers are mostly Java based - see here. Oracle apparently wants to "universalize" (yuck, what a word) the procedure. Apparently, however, for XE on Windows, they decided that it would be best just to have a plain old .exe. 

Maybe they figured that Windows users who chose the XE option weren't up to installing a JVM? :-). Maybe they used some sort of Byte code-to-exe tool to convert their Java based installer to a simpler Windows exe?

Apart from the CPU, RAM and data limitations in XE, Java isn't included in the database. If I recall correctly (haven't done it in a while), the Linux installer is a Java based one - even though Java isn't in the db. I'm not sure if the installer has it's own JRE or whatnot. 

Basically, Oracle is trying to make installs as generic (univeralize - what was wrong with the word "generic"?) as possible but has decided to keep the .exe paradigm for Windows.