This is very relevant when the ‘right to healthcare’ comes up:
Hit & Run – Reason Magazine
…From the founding until the twentieth century, the American regime assumed that government’s purpose was to secure pre-existing natural rights—such as life, liberty, property, or association. Everyone can exercise such rights simultaneously; nobody’s exercise of his own rights limits anyone else’s similar exercise. Your right to life or to work or to vote does not take anything away from anyone else. We can all pursue happiness at once. Entitlements, on the other hand, require someone else to provide me with the substantive good that the exercise of rights pursues. The right to work, for example, is fundamentally different from the right (entitlement) to a job; the right to marry does not entitle me to a spouse; the right to free speech does not entitle me to an audience.
That’s an explanation which is both fair and makes sense to me.