In the CALLER ID section, you can default (static) or dynamic Caller IDs that will be used across different campaigns.
A default caller id is the caller id that will be used and sent out if there is no match of dynamic caller id.
A dynamic caller id is a caller id that can be assigned to a campaign. In that campaign, any phone number that is called is checked for its area code. if the area code matches one of the assigned dynamic caller ids, the corresponding caller id will be used when calling the number.