This means that the prosecutor is obliged to initiate a prosecution if he or she considers there to be sufficient evidence to prove that a crime has been committed and that a certain person has committed it.
This in turn means that not even the victim of the offence can decide what is to happen in connection with the investigations. In other words, there is nothing on the lines of “withdrawing the charges”. The prosecutor must make sure that the crime is investigated, irrespective of the feelings or wishes of those involved.
The reason for this is that society has an interest in ensuring that the perpetrators of the crime are also tried for it. Exceptions are made for certain offences where it may be felt that the interests of the general public in instigating legal proceedings are not strong enough. Examples of such offences are defamation, breach of domiciliary peace and crimes of unlawful appropriation, or stealing, within the family (i.e. theft etc.).