When some orchestra is playing some concerto or symphony or something, What kind of scores do flautist, violinists, cellists,........etc. play from ???

Are they the ones that contain only their parts, or ones that contain, in parallel, all parts of other instruments including theirs, or what?

They're usually only their parts, I think. Sometimes they get other instruments cued in.

Usually their music contains only their own part. Sometimes they have the music for all the instruments parts, for example, all the clarinet parts but not very often.

The instruments in the orchestra generally only have their own line on their part. Occasionally, another instrument's line is cued on the same part.

An exception would perhaps be in string parts. Every now and again, the string section is required to divide itself and play separate lines. In this situation, there may be 2 or 3 staffs on the part, but all of them will be for that section only.

The "score" generally refers to the part with every instrument's line on it, read by the conductor.