what activity is done in Acceptance Testing, which is not done in System testing to ensure the Customer requirements?

Main objective of both system and acceptance testing is ensure all the functionalities and requirement are implemented correctly or not. In Acceptance testing. real time test data is used, usually acceptance testing is done by client or clients representative. Here client will check the all functionalities. But in System testing. - project team and testing team should do testing. Here we have to do all system testing like load, stress, performance etc. - Its not mandatory that we have to use real time data again its depends on the type of application.
a) Acceptance test is executed by users where as system test is executed by the testers.
b) Acceptance test is the responsibility of the client and is a final check point to accept or reject the software.
c)Acceptance testing involves the actual production environment where as system testing simulates the production environment
d) Acceptance testing involves testing the acceptance test criteria mentioned in the Acceptance test plan and verifying that the product meets those criteria where as system test involves testing the entire system and verifying the performance as a whole.
e) System test is carried out when the entire system is ready where as acceptance tests can be carried out at pre - defined intervals.