Are all constellations wired at present? What's the difference between a constellation and a star?

Astronomy stipulates the official names of 88 constellations, but in fact, of course, there is no wired connection between the stars, which is the imagination of ancient people and present people. Most of the stars we see are constellations, that is, connecting those relatively bright stars with human imagination to help them name. In fact, even if two stars look very close from the earth, they may be far apart. Very far away, that is to say, the stars are originally in three-dimensional space, but in our view, they are on a two-dimensional celestial sphere.