[TYPO3-english] Can same TYPO3 source be used for multiple sites?

[Mr Learner]

Hi Everyone,
I'm trying to understand if the same TYPO3 source can be used for multiple
sites. Currently I've only a TYPO3 site running on 4.5 version. If I need
to setup another site on the same version, can I make use of the same
source or is this source is tagged to this site and cannot be used for
others? With my understanding for each site we need to have a copy of its
own source files as they are tagged, not sure if I'm right and trying to
find an answer. Thanks.

Raj.