How does the R/3 System integrate all the application modules? | SAP-SD

Integration of all application modules has been done by the R/3 basis System.
This System helps in the integration of various modules in the following manner:
=>    Guarantees the optimal integration by providing runtime environment
=>    Provides administration tools for the entire System
=>    Provides equilibrium architectural framework for enhancing the System
=>    Provides portability of complete System