What is a type of offensive operation that destroys or defeats enemy forces, seizes and secures terrain, or both?

The type of offensive operation that is characterized by its goal of destroying or defeating enemy forces, seizing and securing terrain, or accomplishing both objectives is an attack. This operation is fundamental in military strategy, as it is designed to bring about a decisive outcome against opposing forces by engaging them directly.

The attack can be conducted with varying levels of planning and coordination, but its primary focus remains on the offensive aspect—actively seeking to engage and overwhelm the enemy, which aligns with the intent to achieve specific tactical or operational goals, such as capturing territory or neutralizing threats.

While other options represent different facets of offensive operations, they do not encompass the comprehensive objective of directly engaging and defeating enemy forces while securing objectives. This makes the attack the most encompassing answer that fits the description provided in the question.