Legal Question in Real Estate Law in California

It is the core agreement of an assignment of a lease. When a tenant has a lease and they want to get out of it without breaching the lease, and so they want to substitute someone else (or another company if a commercial lease, which this probably is since 4-year residential leases are not normal) they can assign the lease or sublease. If all goes smoothly there's little difference between the two, but when some legal complications arise the difference can be important. In a sublease, the master lease remains in effect between the landlord and the master tenant, and (usually subject to landlord consent) the master tenant then leases the property to a sub-tenant. The sub-tenant has no contractual relationship with the landlord, and if the master tenant breaches the lease, the sub-tenant has no recourse. In an assignment, the landlord agrees for a new tenant to take over the master lease directly. Commonly the old tenant is required to remain liable for any breach of the lease, essentially becoming the guarantor of the new tenant's performance of their obligations under the lease. An assignment rather than a sublease is also common when a business is sold that will continue to operate in the leased premises under new ownership.