Consulting as a general label can feel very vague, especially given that it is a huge and diverse industry. There are many different types of consulting firms and areas of practice within one firm. Some management consulting firms specialize in giving advice on business strategy and operations (downsizing, acquisitions, restructuring) while others are known for their expertise in specific industries like technology.
No matter the firm or the focus area though, consulting firms mainly run on their people and the intellectual capital they possess.