Assignment Rules

 Assignment rules use to automate  organization’s lead generation and support processes(Case assignments).

1. Lead Assignment Rules—Specify how leads are assigned to users or queues as they are created manually, captured from the web, or imported via the Data Import Wizard.It automatically assigns leads to users or queues based on criteria you define. You can create multiple rules with different conditions, but only one rule can be active at a time.
   
2. Case Assignment Rules—Determine how cases are assigned to users or put into queues as they are created manually, using Web-to-Case, Email-to-Case, On-Demand Email-to-Case, the Self-Service portal, the Customer Portal, Outlook, or Lotus Notes. It automatically assigns cases to users or queues based on criteria you define. You can create multiple rules, but only one rule can be active at a time

if your organization uses record types, the assignment rules determine the record type when a case is created manually or imported without a specified record type. When no assignment rules apply, the record type of the case owner is used. When the default case owner is a queue, the queue owner's default record type is used.