There are options features that you might not have enabled during the installation but now you need them. Identity Governance allows you to add these features without reinstalling Identity Governance or running the installers again.
Section 11.1, Configuring SSL/TLS Communication after the Installation
Section 11.2, Manually Generating the Database Schema after the Installation
Section 11.3, Enabling Auditing after the Installation
Section 11.4, Enabling Email Notifications after the Installation