Eternity
Part of speech: noun
Definition: Existence without end, infinite time. A period of time which extends infinitely far into the future. (metaphysical) The remainder of time that elapses after death. A comparatively long time.
Example sentence: Politics is for the present, but an equation is for eternity.
Infinity
Part of speech: noun
Definition: Limitlessness, unlimitedness, something which is growing without limits or bounds.A number that has an infinite numerical value that cannot be counted.A number which is very large compared to some characteristic number. For example, in optics, an object which is much further away than the focal length of a lens is said to be "at infinity", as the distance of the image from the lens varies very little as the distance increases further.The symbol ∞.
Example sentence: I'm not going into infinity. I'm going into low earth orbit.