Rights are a social construct; a set of mutually agreed limits of activity. In the theory of natural rights, members of society agree to respect one another's life, liberty, and property. (There is a reason for these three, in that they are all related to each other. For details, read Rand.)
There ARE other rights theories. For example, there is the "might makes right" concept, in which the strong rule the weak, and the "divine right of kings" theory, in which rulers derive their power from some deity. The problem with these is that unless you are strong or a king, you are screwed!
There is also the idea that rights are cumulative; that is, that groups have more rights than any individual in the group. (This is the current working model in our society.) Again, this is great, IF you are in the majority, but if you are in the minority, you're unlikely to fare so well.
The trouble with all of the rights theories other than equal rights of life, liberty and property is that the most productive members of society stop being productive. After all, why bother producing, if the product of your labor is going to be taken away from you by force? Therefore, of the various models, the best overall for society as a whole is the idea of equal rights for all, with individual actions limited where those actions impinge on the equal rights of others.
Bottom line: for a successful, productive, and peaceful society to function, all members should be secure in their lives, property and liberty.