BASIS Module: SAP ERP BASIS module covers the ERP Basis and Security Technology. ERP BASIS means a ‘Basis Administrator’ or ‘ERP System Administrator’ it should include system administration tasks such as

Managing the database
Transporting development and configuration objects from one SAP system to another
Monitoring system performance to ensure no interruption in system stability occurs in the SAP production environment
Installing and upgrading the software on the servers, and system security
BASIS Security refers to both application securities in the SAP Runtime environment and the system access outside the SAP Runtime environment
The user accounts defined for users in the SAP Runtime environment are secured by roles that grant authorizations to them
SAP Authorizations control access to transactions. For example, a user may be able to create sales orders, but only for their specific sales area, sales office and customer.