'Give' is an extremely basic and general word. 'Supply' is more specific. If A supplies B with something, you know that: - B needs this product or service - there is an agreement between A and B about this, usually involving payment - A supplies B repeatedly, at regular intervals, or whenever the supplies are needed

Hmm, this is hard but excellent question. From what I know, "supply" is usually for something very serious like giving something to refugees and military. "Give" on the other hand is usually used for simple things without any serious tone. E.g. 1. I am going to give him some of my sweets later. 2. My brother gave me some toys for Christmas It would sound strange to use supply for the sentences above. 3. The division was supplied with enough fuel for a whole fortnight. 4. He intends to supply the refugees with enough food for the whole month. Supply tends to have a "with" before the object that is being supplied while "give" doesn't. "Give" can be used in sentences 3 and 4 but it would sound a bit softer.

Supply: to make something available for use , provide (something provided as a service -> water supply)