Spaceflight is considered to be the one defining step of modern galactic societies, but it is itself a vast topic covering several fundamentally different aspects. There are different ways to solve the problems that come with the wish to travel beyond ones planet and some have been more succesful than others. However, the basic physical principles are always the same and often the same solutions are applied independently.
Orbital drops are by far the cheapest means of orbital traffic, but come with the limitations of being restricted to space to ground transfer. Essentially, material is thrown towards the surface of an astrological body by the power of its own gravity. If enough of an athmosphere is present, inexpensive parachutes can be used to slow down the drop pods to avoid destruction upon impact. Otherwise, boosters will have to be used, propelling the pod durings its descent. Similiar devices are also necessary to guide the drop pod to its landing spot.
Shuttles are any kind of vessel that can land on an object with considerable own gravity, like a moon or even a planet, and leave it using its own propulsion. The great advantage of a shuttle is its flexibility, requiring no additional infrastructure and thus allowing it to be used to dispatch from spaceships in orbit of their target or to provide orbital trafficking at less developed colonies.
Its main disadvantage are the high costs of operating, requiring an ever greater amount of energy to reach space the higher the gravitational pull. Shuttles are therefore usually small and carry little weight when compared to other means of orbital spaceflight. If the planet or moon they are operated on possesses an athmosphere, they often feature wings to exploit the lift of conventional flight for as long as possible.
Mass drivers consist of long magnetic rails that end in slight upwards ramp, designed to accelerate spacegoing vessels on a planet surface until a speed is reached at which it is capable of leaving the orbit. While they require some space to function properly, mass drivers are considered a viable and relatively cheap way to transport large amounts of matter into space. They, however, are unable to transport anything from space to the ground and therefore tend to be used on worlds that export large quantities of material, but import little and have only limited traffic of living beings. Many mining worlds, for example, operate mass drivers.
While requiring the greatest investment and the highest technological level of all means of orbital spacetravel, spacelifts are the cheapest mode of transportation to operate in the long term. They are basically a particularily long string woven from a supertensile material with one end attached to a ground- and one to a spacestation. Along this thread, a mobile carrier runs up and down, transporting large amounts of material. On its way to the starbase, the entire carrier can be pushed upwards with relatively crude and cheap means, ranging from simple rockets without any complicated guidance systems (the main string leads the way) to magnetic rails. As usual, the way to the ground is even simpler, as gravity can be employed and speed regulated by simple breaks. This method has the additional advantage that all goods run through a central trade hub, which can be outfitted with particularily good infrastructure, increasing the effectivity of orbital travelling even further. Additionally, a spacelift can also serve as cable, supplying a planet with energy from orbital power stations, avoiding more dangerous and less efficient modes of transfer, such as microwaves or lasers.
In theory, interstellar travel is possible without further technology, utilizing only the slower-than-light engines of current spacecrafts. This, however, means a travelling time of several years or even decades between two stars and is thus hardly ever employed. Many civilizations use it in automatized exploration of the galaxy to find planets suitable for colonization, but other than that it is rare. In times prior to the developement of wormhole technology, some species employed slower-than-light flight to other stars in large self-sufficient ships or in combination with cryogenic technology to found largely independent colonies in nearby stars, but the limitations of this mode of travel remain crucial.
Considered to be the only viable option for intergalactic travel, many species independently developed wormhole technology with almost identical designs. Since the underlying principles of wormhole travel are the same for every civilization, each advanced species seeking to reach the stars began constructing similiar gate structures. Wormholes work by bending spacetime to a point where an almost instant connection is created and then stabilize this connection with a number of energetic fields. Once this connection between two gates is established, a wormhole is surprisingly stable and can be kept open at all times with relatively low maintenance costs. The creation of a new wormhole, however, is a risky and expensive process, swallowing enormous amounts of energy. Since objects of mass furthermore influence wormholes, an unexpected object in the planned path can lead to the destruction of a wormhole under construction, swallow the entire construction equipment and may even generate an energetic, high radiation shockwave that can devastate entire systems. It is furthermore the reason why gates are located in distance to planets and stars on the edge of solar systems. Wormholes become exponentially more energy costly and difficult to establish as well as maintain, the larger they are and the largest diameter which is considered to be economical is close to 100 meters, which is why most gates in the galaxy are of this size.