What is a lease assignment and how does it differ from a sublease?

In a lease assignment, the original tenant transfers all remaining rights and obligations under the lease to a new tenant for the entire remaining lease term. In a sublease, the original tenant transfers only a portion of the remaining lease term or space to a subtenant while retaining some interest. With an assignment, the new tenant has a direct relationship with the landlord, while with a sublease, the original tenant remains the landlord's primary tenant and is responsible if the subtenant defaults. Most commercial leases require landlord consent for both.