Identities are the accounts you use outside of The Linux Foundation to contribute to a project. An example would be your GitHub account that you use to submit code to a project. Identities allows you to sync the information from those accounts with your Linux Foundation account. For more information on how to add or update Identities, visit this page. https://docs.linuxfoundation.org/lfx/my-profile/update-identities
Affiliations are the actual contributions you have made to a certain project. In order to see this information, you must have your identities properly completed in the Identities section. On how to update your Affiliations visit this page for more info. https://docs.linuxfoundation.org/lfx/my-profile/update-affiliations