It's quite simple, there are several ways to archive the same thing.
For example, we can already travel on Earth using bicycles, motorcycles, cars, aeroplanes or boats, some of them faster than others.
Some FTL are faster than other FTL but civilizations doesn't want to share their technology.
Maybe each one has a diferent advantage and disvantage. For example:
- Warp drive: doesn't need to precalculate coordinates before launch, but it isn't very quick and also it's weak to gravitational anomalies like planets or starts (isn't safely use it inside gravity wells). Also, it can be detected.
- Jump drive: it needs vastly precalculations before launch and only works on specific and strategy Lagrangian points in the solar system. But due be used in so specific places of the gravity well from the start, it can use this gravity as a catapult and travel long distances extremely fast without being detected. Sadly it needs a prior scanning in the solar system.
- Hyperdrive: faster than warp drive and more difficult to detect, the hyperdrive could be a good travelling system if it doesn't have the disadvantage of can be deactivated by hyperspace inhibitors.
- Hyperline: using a similar principle to hyperdrives, this drive doesn't work anywhere instead, it uses the hyperline maps between a different solar system like highways to archive very fast travelling. Some hyperlines between systems are faster and safer than other ones. Some systems doesn't have natural hyperlines and they must be build with a very expensive technology. Also, you must to explore the galaxy in order to find them.
- Stargate: creating an artificial wormhole can be an extremely quick travelling way. Sadly each stargate has a specific size and bigger ships can't travel on it. Also, stargates can be captured or destroyed by the enemy, and build one require a lot of calculations.
Also, you can add cooldowns or warmup times for each drive based on a flat number or proportional to the travelled distance, the speed and/or duration at your choice.
Each method works using a different principle.
Warp drive (Alcubierre drive)
The sci-fi warp drive or the currently theorized Alcubierre drive use the principle of space-time distortion (primarily based on a gravitational distortions)
Wikipedia has already explained it perfectly.
Rather than exceeding the speed of light within a local reference frame, a spacecraft would traverse distances by contracting space in front of it and expanding space behind it, resulting in effective faster-than-light travel. Objects cannot accelerate to the speed of light within normal spacetime; instead, the Alcubierre drive shifts space around an object so that the object would arrive at its destination faster than light would in normal space without breaking any physical laws.
The hyperdrive travel to another planer when the is not cap of speed or the plane is smaller than our universe allowing travel from one place to another using a shortcut.
The idea of a hyperdrive in most science fiction relies on the existence of a separate and adjacent dimension most commonly called "hyperspace" [...]. When activated, the hyperdrive shunts the starship into what appears to be another dimension, where it can cover vast distances in an amount of time greatly reduced from the time it would take in "real" space. Once it reaches the point in hyperspace that corresponds to its destination in real space, it re-emerges.
It's usually explained as:
Distances in hyperspace may be smaller than or geometrically inverse in relation to real space; it may provide a shortcut between two points in real space, thus effectively increasing the ship's speed by reducing distance travelled rather than time taken; perhaps the speed of light in hyperspace is not a speed barrier as it is in real space
And the hyperspace could be described as:
It is typically described as an alternative "sub-region" of space co-existing with our own universe [...]. [It] is most succinctly described as a "somewhere else" within which the laws of general and special relativity decidedly do not apply [...]. [...]
Instead of using the hyperdrive anywhere, it only works between specific "hyperlines" between gravity wells (solar systems). In order to travel you need to have one hyperline map that shows you the faster and safer hyperlines for your travel. Hypelines can be built artificially in solar systems without lines with the most expensive technologies.
I couldn't find an easy explanation on Wikipedia so I'll write my own.
The jumpdrive produces a distortion between two different points in the space-time effectively "touching" them, the destiny and the start point are merged for an instant being the same location at the same time. Then, the ship moves through this joint and reaches its destination.
A jumpgate or stargate, is a device able to create an Einstein–Rosen bridge portal (AKA wormhole), allowing fast travel between two points in space-