Complex sentence: The anode is an element that loses electrons (reducing agent), thus oxidation always occurs in the anode, and the cathode is an element that gains electrons (oxidizing agent), thus reduction always occurs in the cathode.
Split into simpler sentences: The anode is an element that loses electrons (reducing agent) and causes oxidation to occur in the anode. The cathode is an element that gains electrons (oxidizing agent) and causes reduction to occur in the cathode.