Windows MUI/LIP Knowledge Center
All your answers are here.
What is the difference between LIP and MUI?
The main difference is in the level of localization in comparison to MUI packages: LIP packages provide the desktop user with an approximately 80% localized user experience. In addition, LIP doesn't allow users to switch languages
. Once a LIP is installed, all users using that machine will have the same User Interface (UI) language.
LIP relies on the same resource-loading technology MUI is built upon, and installs on top of the English version of Windows XP Professional (in most cases).