What is difference between Tech Trading and Tech Brokering?

Tech trading: You can trade technologies away you have researched yourself.

Tech Brokering: You can trade any technology you have. Including the ones you have acquired (like stolen, traded with an other partner, etc) besides the ones you developed yourself.

To be clear, on tech trading you can only trade techs you have researched yourself, so that means you cannot get or acquire other techs since you didn't research them, correct?

With Tech brokering I can be the lowly tech disadvantaged Iridium and "BUY" for a bazzilion credits, Planetary Invasion, Death Beams and ULTRA large ships which are things 2 ages ahead of me, is this correct?

Strictly speaking, Tech Brokering should be where that guy trades to that other guy, and you sit in the middle and take a cut.  A tax on both your trade routes!!

Brokering should be, like Gilmoy said, you don't have the tech but know someone who does and know someone who wants it, you set up the deal and take a cut in some form.  I didn't pay close attention to the stream to say this is the way it will work.

I would love to be able to do that in large maps get to the middle and trade techs with everyone.

I wouldn't be surprised it works like trading techs you have vs techs you researched.

Is it just me, or am I seeing a contradiction in definitions?  Perhaps Gilmoy has it the only way it could be.

T: "I'll trade you 'Beam Weapons" for 'Missiles.'"

A: "Since you have not researched 'Missiles' we can not trade them to you. You will have to get a broker."

Let say you are playing the Terrans and you want to trade with the Iridium. The Iridium have developed "Xeno Irrigation", and acquired "Advanced Construction" from the Alteran - it does not matter whether it was traded/stolen/etc.

Tech trading: You can obtain the "Xeno Irrigation" because the Iridium have developed it themselves. Likewise you can not obtain "Advanced Construction" from them because they did not research it.

Tech brokering: You can obtain both the tech from the Iridium because the have it. It does not matter whether they research it themselves or obtained it through other means.

Think of it like this: Tech trading you need to talk to someone who actually researched it, Tech Brokering: you need to talk to someone who simply has the tech.

With both options you can buy advanced techs from others, the only difference is from who you can obtain a certain tech.

Of course, it not only works in acquiring tech but also in which techs you can trade away.

There is no contradiction.

Tech trading:

T: "I'll trade you 'Beam Weapons" for your 'Missiles.'"

A: "Since we have not researched 'Missiles' ourselves we can not trade them to you."

or 

T: "I'll trade you 'Beam Weapons" for your 'Missiles.'"

A: "Since we have researched 'Missiles' we can trade them to you."

Tech Brokering:

T: "I'll trade you 'Beam Weapons" for your 'Missiles.'"

A: "We have 'Missiles' we can trade them to you."

Edit: Further complicating the issue is how Wictionary seems to show "broker" as a specific subset of "trade", in that brokering always involves a middle man, while trade includes all of the definitions of broker ... and much more.

Also, it is hard to see where trade would require you to be an original owner of a tech (such as having researched a tech). As long as you possessed the knowledge, regardless of , why couldn't you trade it?

It still does not make any sense. For tech trading you are saying you have to have 'already' researched it in order to trade it, however that makes the actual trade (impossible) since the party who wants it cannot get it if they did not research it. 

Tech brokering I understand. I have Market Centers in (age of Expansion, which I am in.) which I trade plus some cash to get Planetary invasion (in age of war) from the Drengin (assuming they are willing). This was how it was in GC II. 

Tech trading does not appear to make sense as I have something that I cannot trade to you unless you already researched it? That seems absurd. 

It just a game mechanic to control how technology spreads.

No Tech Trading: 0-order spread of technology. You want a tech, research it yourself.

Tech Trading: 1-order spread of technology. You want a tech, research it yourself or obtain it from someone who has researched it.

Tech Brokering: n-order spread of technology. You want a tech, research it or obtain it from anyone who has it.

Let say you are Terran and you have developed "Advance Construction".

With neither Tech Trading or Brokering: You can not trade it away to anyone.

With Tech Trading: You can trade it to anyone, but after that they can not trade it to someone else.

With Tech Brokering: You can trade it to anyone, but after that they can trade it away to everyone.

The party who wants it can get it from you, as long that you have researched it. If you got it through trade yourself, then you can not trade it to that party. So it is not that party that needs to have researched it, but you.

With tech brokering this limitation is not applicable.

Ok that is much more clear. Again in the example. If the Drengin have Planetary Invasion (Age of War) and they are the ones who got it and did not trade for it, they could give it to me, even if I was in a lower Age or not near it in unlocks...

Since they researched it themselves it does not matter whether tech trading or tech brokering is active. So you can get it from them.

What you are saying is that if I didn't research "automobiles" or some component there of, I could not sell the car I bought from a new car dealer (a trade of money for the car) to someone else.

In short, I am saying that your definition of "trade" just doesn't make sense in the real world, and that makes it impossible for me to buy into a mechanic like yours in a game.

Certainly there are better ways to control how technology spreads, if that is the real intent of putting in such a mechanic; such as, even if you get tech "L" in a trade when you don't have tech "F", then tech "L" does you no good because you still can't build anything using tech "L", or you just can't trade for tech "L" because you don't have tech "F" yet.

I am not saying that at all. What i am saying is "if you didn't research 'automobiles' then under tech trading you can not sell the tech 'automobiles' to someone else". If you trade money for a car then you are free to trade the car to someone else for whatever they are willing to pay for it.

Tech "F" does not matter. If you can obtain tech "L" through trade then you can use it. With tech trading you can not trade "L" to someone else, but with tech brokering you can.

Originally the distinction was introduced in GalCiv2 because players complained that once they traded a tech away to an AI all AI's got that tech fairly quickly. To limit the tech spread from AI to AI to AI to etc, etc, the "Disable Tech Brokering" option was introduced.

So you are also saying that if you sell me a warship I can't reverse engineer it to get the techs used to build that ship.

GC isn't the only game that has had trouble with "tech spread", but I don't think disabling Tech Brokering is a valid way to suppress it. I don't think it should be suppressed at all. It sounds too unreal. Which is probably why they made it a toggled option in the first place.

Correct

In GalCiv2 it was up to the player whether to allow brokering or not; so i hope this will be the same in GalCiv3.

I personally never found the need to disable it, because the AI would quite happily trade their techs for money and/or influence. So i kept my techs, while acquiring theirs for useless gold.

The problem was that the AI did not grasp the true value of a tech is not the tech in itself, but in the application of said tech. I hope that the AI will be a lot smarter of when and for what to trade techs.

The scenario that disallowing tech brokering avoids is this: I am the Terrans and I trade the Drengin tech A for tech B. I then go to each of the other 6 races and trade them tech B for another tech, meaning that for tech A I just received 7 techs. This is further comlicated by the fact that I can then go and trade tech A to the Iridian Corperation for Tech C, trade that tech around and get another 7 techs, rinse and repeat. Now, that literal situation is unlikely, but it shows how easy it is to exploit tech brokering. By spreading a few techs around, giving no one a distinct advantage, you can claim a bunch of extra techs for yourself. This is still an issue with tech trading, but brokering multiplies the problem exponentially. 

Example:

Civ A is my friend

Civ B is neutral

Civ C is my enemy

I get an awesome weapon tech I don't want my enemy to have. I won't trade it to Civ C but I can trust Civ A with it. If I trade my awesome weapon to Civ A they might trade it to Civ B who then trades it to Civ C. Now my enemy has it. That's how brokering can work against you. You'd either have to never trade that weapon tech, or also trade it to your enemy because they'll get it anyway so you might as well get something from them in return.

If brokering is not allowed then you can trade the super weapon to your friend Civ A and not worry that it with end up with Civ C. Also, you could trade them a tech they would get anyway (if it's possible to see what someone is researching) so they can't trade it away themselves.