Is vitreous detachment similar to retinal detachment?

Yes: A retinal detachment needs to repair surgically otherwise your eye sight would be bad, a vitreous detachment is when the fluid in the back of the eye comes off it's retina attachment and is not sight threatening but may cause a retinal whole or tear, which may lead to a retinal detachment if not diagnosed and treated early.

Yes: The vitreous jelly that fills the eye and attaches to the back wall of the inside of the eye (the retina) will detach from the retina with age (posterior vitreous detachment). At that time or days/weeks later a retinal tear or detachment may or may not occur as well. The latter conditions require urgent treatment before blindness ensues. A vitreous detachment is not treated.

Not the same: Retinal detachment is when the retina, the seeing part of the back of the eye, lifts off its moorings. The vision drops, and if the retina is off too long, may lose all function. Vitreous detachment is when the gel filling the back of the eye lifts off the retina. This is usually benign although can be symptomatic briefly and commonly causes floaters. They are quite different.