A high assurance session is a type of session security level that requires users to verify their identity using a second factor of authentication, such as Salesforce Authenticator, a verification code, or a security key. Administrators can configure certain actions or permissions to require a high assurance session, such as exporting reports, viewing encrypted data, or accessing connected apps.
If users are able to run reports but are taken to a login screen and prompted for additional verification when they try to export a report, it could be because exporting is configured to require a high assurance session. This means that users need to use a second factor of authentication to export reports, even if they have already logged in with their username and password. Reference: https://help.salesforce.com/s/articleView?id=sf.identity_verification.htm&type=5 https://help.salesforce.com/s/articleView?id=sf.security_sessions.htm&type=5

An authentication app is a mobile app that generates verification codes for logging in to Salesforce or other services that require multi-factor authentication (MFA). A username and password are also required for logging in to Salesforce, but they are not sufficient for MFA. Reference: https://help.salesforce.com/s/articleView?id=sf.identity_auth_apps.htm&type=5

To create a training sandbox with 160MB of test data that needs to be refreshed every other day, NTO should use either Partial or Developer Pro sandboxes. Partial sandboxes have a storage limit of 10GB and can be refreshed every 5 days. Developer Pro sandboxes have a storage limit of 1GB and can be refreshed every day. Both sandboxes can include test data from production. Reference: https://help.salesforce.com/s/articleView?id=sf.data_sandbox_environments.htm&type=5