For all intents and purposes, it's the same thing. A person who is the victim of one of those two has been denied their tenancy rights without the benefit of court process. Lockout might be just the changing of the locks (what is called constructive eviction), while an eviction implies a tenant's belongings are removed. But the legal effect is the same. There can also be situations where conditions are so horrible (i.e., no heat) that a tenant has also been constructively evicted.
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