Employment relationship... who is the buyer and the seller? Forum

[stocksly33]

I just did a hypo from siegel's and it says the employer is the seller, and the employee is the buyer... I inferred that because Siegel's had the employer using impossibility/impracticability defenses; but i thought those were just seller's defenses. And the employee used a frustration of purpose defense; which I thought was only a buyer's defense.

That doesn't make sense to me. isn't the employer buying the employee's labor for $? and the employee is selling his/her labor to the employer for $?