Ok im sure this is a dumb ? but I want to get a spare shift and brake cable for my hybrid,road and fat bike...are the shift and brake cables the same ?? And do they come in one length ?

Brake cables are thicker than shifter cables, likely because they transmit more force. Shifter cables use the same head regardless if road or mountain. Brake cables have different heads for road and mountain levers.

If you have any Campy stuff, they require Campy specific cables.

Cables come in one length and you cut them to fit. I want to say 2m or so is typical. Get some cable end caps too. They come in different sizes for brake and shifter cables.

Shift and brake cables are very different and are NOT interchangeable. It is very dangerous to use shift housing on brakes, it can fail without warning upon hard braking, just when you need it the most.

Here's pretty much all you need to know about cables: Cables

Tat attachment doesnt work ??? So if I buy a shift cable and a brake cable it should work on all my bikes ? They all have Shimano stuff

The cable head for road and mountain brake levers are different so you'd need three if you have a hybrid and road bike.

is that the brake AND shift cable are diff ? If that the case ill need 4 right...a brake and shift for the road bikes and a brake and shift for the hybrid

Cables come in a variety of lengths, but the longer ones are mostly of interest to tandem and recumbent owners.
Cable info from Bikeman: Bikeman: Cables

Remember "cables" consist of two items, the housing and the inner wires. As noted both are specific to either brake use or shifter use and should not be interchanged.

Shift housing is "compressionless" and has the reenforcing wires more-or-less parallel to it's length. Is it does not change length when bent in a reasonable radius to make index shifting reliable but does not have great burst strength as it doesn't need it. Shift housing is most commonly 4 mm outside diameter.

Brake housing has it's reenforcing wires wound in a tight coil which give it the essential burst strength. It's typically 5 mm in outer diameter.

Shifter inner wires have a single end and are smaller in diameter than brake wires, typically 1.1 or 1.2 mm.

Brake inner wires are thicker, typically 1.5 or 1.6 mm in diameter, and have two end shapes, one for road bikes and one for MTB use. Many brake wires come with a different fitting at each end and you cut off the unneeded one.

Good quality brake and shift housing is lined with a smooth plastic or teflon liner. Brake and shift inner wires may have a teflon coating but this is not essential and can cause troubles with slippage at the pinch bolts if it isn't scraped off at that position.

Shimano and Jagwire are good brands for both wires and housing.

So i can get a universal brake cable and a shifter cable and should be set for both hybrids, and road bikes yes ?

Yes. The shift cables are both the same. The brake cables, if they have both fittings, will work on both bikes.

ok so my hybrid has the trigger rapid fire shifters..and the road bikes have the paddle type on the brake lever,,,but they BOTH use the same cable ?

Yes, shift cables are the same for both; only on brake cables do the heads differ.

Look at your brake cables, where they attach to the levers, and compare it to this pic. To see the end, squeeze the lever and look inside.

Not to beat a dead horse or confuse things, but there are now some cyclocross brake levers, single speed brake levers and TT brake levers that use a brake inner wire with the thickness and strength mentioned above with a head that looks like a shift wire head. Hard to find as I found out trying to replace a cable on my single speed. What I found was a FSA Cable Brake Inner Wire Ss Vision Head.