The Salyut space stations are themselves spacecraft, orbiting the Earth at an altitude of around 200km to 270km. Each of the Salyut stations was launched as a spacecraft, by a Proton K carrier rocket, and then used its own engines to reach orbit. Expedition crews and visiting cosmonauts were transported to the stations on Soyuz crew spacecraft launched on Soyuz carrier rockets.

The later stations, six and seven, were supplied by un-crewed Progress spacecraft also launched on Soyuz carrier rockets. These stations were also visited by un-crewed TKS spacecraft for testing purposes.

Reference: Wikipedia  -  Soyuz Spacecraft,  |  Progress Spacecraft  |  TKS Spacecraft

The mission of a spacecraft to the stations has five main steps:-

The first step is to launch the spacecraft and overcome the Earth's gravity so that it can be placed in a similar orbit to the station. The launching method varies depending on the size and type of craft being launched.

The launch vehicles are generally multi-staged. The first stages use a number of large engines to lift the weight of the spacecraft, launch vehicle and fuel. When the first stage fuel is used the stage and fuel tanks are discarded to be destroyed. Subsequent stages use smaller engines to enable the spacecraft to reach orbit.

Once the spacecraft is in orbit it needs to catch up and match velocity with the station. The launch vehicle can only place the spacecraft in particular orbits relative to the launching place on Earth. Spacecraft then use their own rocket engines to catch up to the station, match its orbital altitude and speed and dock with the station.

Using remote control from the station or Earth, small rocket engines (thrusters) on the craft are used to guide it to the docking point. After initial contact the docking mechanism pulls the craft in and securely locks it to the station with an air tight seal.

Un-docking is the reverse procedure to docking and uses a similar method. After un-docked the spacecraft uses its thruster to move to a safe distance clear of the station and then uses its main engines to slow down for de-orbit.

When the spacecraft has slowed sufficiently gravity pulls the craft into the Earth's atmosphere. If the craft is designed to return to Earth it uses heat shields to slow it's speed amd parachutes for its final descent. Progress un-piloted craft are not intended to return to Earth and are destroyed by the friction of entering the atmosphere.