An arrest is when police restrain and take someone into custody for the purpose of questioning or charging them with a crime. The process is different in every country. However, all countries have laws that limit the authority of the police to deprive people of their liberty.
Generally, the police can only arrest you if they have probable cause that you committed a crime and that you are the one who did it. This requirement, enshrined in the Fourth Amendment of the United States Constitution, is designed to restrain the power of the police and prevent them from using their powers arbitrarily or in violation of basic human rights.
When you are arrested, officers should tell you that you have the right to remain silent and to ask for a lawyer before being questioned. It is also illegal for the police to promise a lighter sentence in exchange for a confession. You should also never accept a bribe from the police, including money or gifts. It is also a criminal offence to resist arrest by the police.
When an accused person is arrested, they are usually taken to Central Booking (New York City has five locations) and fingerprinted. They will be asked to give their name and address and may have a photo taken. They will be questioned about any suspected crimes and given a Voucher form listing all their property, except for contraband items. The police may hold their phones for them so they cannot make phone calls to their families and lawyers.