How can we list all the available activities in SAP?

How can we list all the available activities in SAP

What is a user buffer?

What is PFCG?

Can multiple roles be assigned to a single user?

What is the difference between SE16 and SE16N?

What is LDAP?

Name few password related profile parameters?

As an administrator, what steps should you perform before restarting the SAP server?

What is specific about the Enqueue work process in SAP?

Where are table buffers stored?