A Catalog and a Catalogue have the same meaning with the different spelling. Catalog is mostly used in American English, whereas, Catalogue is used in British English.

Looking refers to the activity of directing eyes on the object. Visual perception is obtained about the object by the act of looking. On the other hand, staring refers to the looking but specifically for a...

Intelligence is the quality of being intelligent. It is the quality of a human being to be well-informed and smart. Artificial intelligence, on the other hand, are computers that can be well trained to think...

Forget is to dismiss something from mind. Forgot is the simple past tense of forget. Whereas, forgotten is the past participle of forget.

Optimum means the quality, quantity or degree of something which is best or most favorable. Maximum can be defined as the highest, largest or biggest possible of something.