What was ‘natural and inalienable rights’?

Ans1-.The constitution began with a Declaration of the Rights of Man and Citizens
2- Rights such as the right to life, freedom of speech, freedom of opinion, equality before law were established as ‘natural and inalienable rights’, i.e., they belonged to each human being by birth and could not be taken away
3-It was the duty of the state to protect each citizen’s natural right.