Greetings Jay
Allow me to expand on Adam's reply.
DataFabric Manager (DFM) is the server component. This component is the heart of the system and runs on a dedicated (no other applications installed) server. Operatoins Manager is the web-based UI that is used to configure/manage/monitor/etc. objects in the DFM database, and is the overall name for the software. Note that there is also a commmand-line interface that is accessible directly on the DFM server itself. Operations Manager also has the components Performance Advisor (included with the package), Protection Manager (licensed component) and Provisioning Manager (licensed component). Your sale/account team should provide more help with identifying your needs and which options match your needs/requirements.
In short: DFM is the heart of the software (server component). Operations Manager is the web-based UI for management/configuration/monitoring. The NetApp Management Console (NMC) provides access to Performance Advisor, Protection Manager, and Provisioning Manager components.
Alex