Consulting has existed for more than a century, beginning with early industrial engineers who advised companies during rapid technological change. Over time, consulting expanded into strategy, management, finance, human resources and digital transformation, becoming a global industry that influences both private and public sectors. Organisations often turn to consultants during periods of growth, restructuring or uncertainty, a trend that accelerated with globalisation and the digital era. The field evolved alongside business schools, new analytical methods and the rise of specialised expertise that companies may not possess internally. At the same time, internal teams have become more data driven and multidisciplinary, shaping a question about when outside advisors add value and how organizations balance internal knowledge with external insight. This debate looks at the historical development of consulting, why it became a major force in modern business, and how companies decide when to rely on external guidance or internal capacity.