Step 1: Strike:
A strike is a collective, organised stoppage of work undertaken by employees/workers to press their demands upon the employer.
Step 2: Lockout:
A lockout is the reverse action: a temporary closure of the workplace, or the employer's refusal to allow employees to work, used as a pressure tactic against the workers.
Final Answer:
A strike is workers refusing to work to press demands; a lockout is the employer shutting the workplace/denying work to pressure the workers.