Shared Long Code can be a 10 digit mobile number through which you can receive SMS on the shared keywords. The keywords would be unique for every customer but VMN can be shared with multiple customers. API and URL forwarding are available. Keywords can be chargeable. 

In Dedicated Long Code, you can have multiple keywords to be created and be managed by VMN application user.  Long code would be any 10-digit mobile number. API and URL forwarding available. There will be one time set-up cost for the new mobile number.