When a spacecraft enters earth's atmosphere, it is totally destroyed and comes down as a single probe, so how can a spacecraft be reusable for new missions?
The Soyuz spacecraft is launched on a Soyuz rocket, the most frequently used and most reliable launch vehicle in the world to date.
That quote "the most frequently used" just means they built and launched lots of Soyuz rockets (more than 2000). None of them were reused.
Reuse is still a new concept. The Space Shuttle was the first reusable launch system: the orbiter and the solid boosters were designed to land intact. As it turns out, it took a lot of work to refurbish them, so a Shuttle launch was still really expensive.
SpaceX have designed their Dragon capsule to be reusable. Now the Dragon consists of two parts: the crew module (which lands intact and can be reused) and the trunk (which cannot land and will burn up during reentry).
SpaceX are working on making the first stage reusable as well: the first stage is equipped with landing legs and it is meant to make a soft landing on a barge in the Atlantic ocean, or even fly back to the launch site and land there.
