Hi Glen,
The Corporate Memory is part of the EDW Core. EDW Core is meant for standardized template-based BI. Corporate Memory is the place for a long term persistent storage of all extracted history (often on Near-line Storage). It is not meant for querying, consider it as a BI life insurance: if anything happens to the data, then it is still available for repair actions.
The Open ODS layer is the inbound layer. It can be BW managed (i.e. data stored in BW) or externally managed (i.e. data stored on HANA). It concerns field level data which can even be real-time replicated from the source system. It can be used for operational reporting but it can at the same time provide services to EDW Core.
Last but not least, please have a look to the document LSA++ for an overview of LSA++.
Best regards,
Sander