In the context of GST, 'furtherance of business' refers to activities that aim to increase or improve your business, taking it to a higher level. This involves goods or services that maintain their identity throughout the business process until consumed. Essentially, any action closely linked to your business operations, whether directly in the process or to facilitate it, falls under this definition.
It is involvement of goods or service in an ongoing business. The said goods or services must reflect it's entity in its original form or otherwise at every stage till it was exhausted in the hands of consumer.
Any activities undertaken by a person in connection with or having a proximate and close nexus to its business is in the course or furtherance of business