Giants, specifically referring to giant stars in astronomy, can vary significantly in their temperature and brightness.
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Temperature: Giant stars can be either cooler or hotter than the Sun, depending on their specific type and stage of evolution. Some red giants, for example, have cooler temperatures, often around 3,000 to 4,000 K. On the other hand, blue giants are much hotter, with temperatures exceeding 20,000 K or more.
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Brightness: Regardless of their temperature, giant stars are typically very bright. They have large radii and can emit a considerable amount of light. The luminosity of giant stars can be hundreds to thousands of times greater than that of the Sun.
In summary, giant stars can be both cool (like red giants) and bright, but the concept of "cool" refers primarily to their surface temperature rather than their overall brightness.