How far confession differs from admission as defined in Indian Evidence Act, 1872?

A confession, is received in evidence for the same reason as an admission, and like an admission it must be considered as a whole. Further, there can be an admission either in a civil or a criminal proceedings, whereas there can be a confession only in criminal proceedings. An admission need not be voluntary to be relevant, though it may affect its weight; but a confession to be relevant, must be voluntary. There can be relevant admission made by an agent or even a stranger, but, a confession to be relevant must be made by the accused himself. A confession of a co-accused is not strictly relevant, though it may be taken into consideration, under Section 30 in special circumstances. Confessions are classified as: judicial, and extra-judicial. Judicial confessions are those made before a Court or recorded by a Magistrate under Section 164 of the Criminal Procedure Code, 1973 after following the prescribed procedure such as warning the accused that he need not to make the confession and that if he made it, it would be used against him. Extra-judicial confessions are those which are made either to the police or to any person other than Judges and Magistrates as such. An extra-judicial confession, if voluntary, can be relied upon by the Court along with other evidence. It will have to be proved just like any other fact. The value of the evidence depends upon the truthfulness of the witness to whom it is made.