A floater is a piece of pigment suspended in the gel of the eye, observable in your field of vision, which you cannot look directly at (it “runs away” when you try to).  Floaters can be anything from dot-shaped shadows to squiggly lines.  It is normal for you to get a few more as you age; it is not normal for a sudden increase in their number.  A sudden increase could indicate a retinal tear or detachment, and you should seek care immediately.