The first is by delivery of the goods, of whatever type, from seller to buyer on or after the first allowable date for delivery (in the US, this date is called 'first notice day'). The seller of the contract, the short, decides whether or not to make delivery in order to settle the contract.
The second, and far and away the most common, type of settlement is by offset. If one is short (i.e 'has previously sold') 5 Dec Wheat, one buys later on 5 Dec Wheat, scores up the profit or loss, and is flat (i.e. out of) the mkt.
The third is cash settlement, as for instance in the CME Lean Hogs contract. Nobody delivers anything to anyone, ever. All contracts that have not been offset on the contract's expiration date are settled ''for cash''. The exchange fixes a final settlement price for the contract in question, and both the owners and shorts of the remaining open contracts calc their profits or losses and either pony up or collect, in a manner defined by the exchange and governed/enforced by the exchange member brokerages.
There are certainly any number of other contracts-in-future when dealing in physical or financial goods. These include spot, forwards, swaps, and switches among other things. None of these are futures contracts. These have different terms and different methods of settlement, although, to be completely fair, there are now a number of futures mkts in various swaps. Still, a swap and a swap future are two different critters.
Different topic ----
I'm not asking how to embed PNG graphics in anything. I have a page, generated by PHP and that blasted 'header' structure, that uses PNG graphics to display the information I want displayed (just an ordinary daily bar chart for ...surprise!... futures prices). This works very well and produces a nice graphical image. No change required here.
What I need to do is to insert **INTO** that page assorted clickable links to other web pages. Ideally, in the best possible case, I'd like these links to be able to use Javascript in order to accomplish one or another 'special' effects. No Java required or desired, and I'll have nothing to do with Active X controls or anything similar.
And that, to quote the odious Walter Cronkite, is the way it is. Grateful for any/all practical advice.
Many thanks again for your patience with my, evidently, poor explanation!