You have the right to remain silent. Anything you say can and will be used against you in a court of law. You have the right to an attorney. If you can not afford an attorney, one will be provided for you.
Anyone who has watched any cop/crime show has heard this. This is what is referred to as the Miranda warning or Miranda rights.
It is a warning given to suspects in police custody before interrogation to inform them of their rights against self-incrimination. If they have understood this right and choose to waive them, and speak to the police regarding the incident, any self-incriminating statements they make may be admissible as evidence in court.
The Miranda warning is required in the United States, but there are equivalent rights in other countries as well.
In the Philippines, the Miranda Doctrine is also followed as shown in Article III (Bill of Rights), section 12 of the 1987 Philippine Constitution (see excerpt below). The Miranda warning is given to persons placed under arrest, whether with a warrant, or without (warantless arrest), in a language or dialect the person knows and understands.
If the person under arrest chooses to waive this right and give his statement, the arresting officer must ensure that the waiver is made in writing and signed by the arrested person in the presence of a counsel.