Workers Compensation is a statutory benefit as per state law provided to an employee or to his/her family due to a job-related injury, illness, or death. The benefit may be wage replacement, medical expenses, employee rehabilitation, or death benefits to the employee's family.
Employers' Liability is the broader coverage of Workers Compensation. It covers employers in case they get sued for alleged business negligence that caused the employees' injury, illness or death. This usually covers defense cost, court fees, settlement, and judgement.
Workers Compensation can be tricky as each state has its own set of workers compensation laws the employers must follow. Texas for example does not require private employers to provide workers compensation as long as the employees are made aware of it. If the private employers gets a government contract, then they will be required to get workers compensation policy for all employees.