VST instruments categorize as orchestral samples, synthesizers and electronic soundscapes, and rock or jazz band scenarios, as well as instrumental effects and sound design. This is why sample libraries can get expensive really fast when you need a full library of sampled orchestral sounds.
Other features to consider are how many instruments the library contains. Are you looking for a small ensemble just to add some depth to your arrangements, or do you need a larger selection of sampled instruments to compose symphonies or scores? Personal intent will play a huge part in which orchestral string VST you choose. 2b1af7f3a8