General Meaning of ‘supply’:
Supply – provide or furnish (a thing needed), provide, meet or make up for (a deficiency or need etc.) – Concise Oxford Dictionary
Supply – ‘Supply’ is that which is or can be supplied, available aggregate of things needed or demanded, an amount sufficient for a given use or purpose – Law Lexicon – P Ramanatha Aiyar
Supply – furnish, substitute for – Collins Gem Dictionary.
Thus, ‘Supply’ is a very broad word.
‘Supply’ does not need ‘consideration’.
Further, two separate legal entities are not required. One branch or division or depot can ‘supply’ goods or services to another branch, division or depot.