The vitreous humor is the clear gel that fills the space between the lens and the retina. On the cow eye, this can usually be removed in a single clump of thick liquid, unlike the aqueous humor which is thin and watery.
Most eye floaters are caused by changes that occur in this liquid. Fibers tend to clump up and cast tiny shadows on your retina which you perceive as floaters. These spots move when you try to focus on them, usually occurring in bright light.