The right to remain silent
“You have the right to remain silent, or Anything you say can and will be used against you in a court of law ”
The phrase with "the right to remain silent", made so popular by the american movies, is actually used in many other countries of the world, not only in America or Australia.
Warnings of a right to remain silent are given in approximately 108 nations around the world.Source: wikipedia.org
Most of the countries that were part of British Empire immortalized upholds the full right to silence, less England and Wales where remaining silent can be considered as being guilty. Though, Scotland is still using it.
This legal principle gives to any individual the possibility to refuse answering questions asked by a person of law (policeman or court officials) as anything it will say can be used, in the end, against him/her. The idea behind this is to avoid self-incrimination, before the real reason for incrimination is well known and before a lawyer will help with the defense (if the suspect can afford one).
If the suspect does not afford a lawyer, the right to remain silent has no reason to apply and the only thing left to do is to answer the police interrogation.
However, even if a person (criminal suspect) can make use of this right to remain silent to help itself and avoid to do things worst (without knowledge, to bring more accusations on its name until a lawyer will assist), is still mandatory to answer on questions related to its name and where it lives.