Which term describes a merger or takeover between businesses?

The term that best describes a merger or takeover between businesses is "integration." Integration refers to the process whereby two or more companies combine to form a single entity or operate under a unified structure. This can occur through a merger, where two organizations agree to come together as equals, or through a takeover, where one company purchases another and incorporates it into its operations.

This concept is key to understanding corporate strategies, as businesses often seek integration to achieve greater market share, improve efficiencies, or eliminate competition. In contrast, while "acquisition" can refer specifically to one company purchasing another, it does not encompass the broader context of mergers, hence "integration" is more encompassing in this scenario. The other terms, like diversification and collaboration, relate to different business strategies that do not necessarily involve the combination of entities like a merger or takeover does.