Difference between 11.0.3368.0 and 11.0.3128.0 for SQL Server 2012

1. 11.0.3368.0 
Full version name 
Microsoft SQL Server 2012 (SP1) - 11.0.3368.0 (X64) 
May 22 2013 17:10:44 
Copyright (c) Microsoft Corporation
Standard Edition (64-bit) on Windows NT 6.1 <X64> (Build 7601: Service Pack 1) (Hypervisor)

2.11.0.3128.0
Full version name 
Microsoft SQL Server 2012 (SP1) - 11.0.3128.0 (X64) 
Dec 28 2012 20:23:12 
Copyright (c) Microsoft Corporation
Standard Edition (64-bit) on Windows NT 6.1 <X64> (Build 7601: Service Pack 1) (Hypervisor)

Remarks:-

Version 11.0.3368.0 include Hot Fix for Microsoft Knowledge Base article number(s) 2833645 for Microsoft SQL Server 2012 (SP1) 64 bit server-pack 1

This hotfix is also known as CU4 for SQL. You can search on google with name KB2833645 to find download for this.

11.0.3128.0  this version is standard installation excluding CU4.