A more thorough explanation:

An investigatory stop, also known as a Terry stop or stop and frisk, is a brief detention and questioning of a person by a police officer when the officer has reasonable suspicion that the person has committed or is about to commit a crime. During the stop, the officer may also conduct a search for a concealed weapon.

This type of stop can be conducted without a warrant or probable cause, but it must be based on specific and articulable facts that lead the officer to believe that criminal activity is afoot. The Supreme Court upheld the constitutionality of the stop and frisk in the case of Terry v. Ohio in 1968.

For example, if a police officer sees a person acting suspiciously near a store that has just been robbed, the officer may conduct an investigatory stop to question the person and search for any weapons that could have been used in the robbery.

Another example could be if a police officer sees a person walking around a high-crime area late at night and the person matches the description of a suspect in a recent string of burglaries. The officer may conduct an investigatory stop to question the person and search for any stolen property or weapons.

These examples illustrate how an investigatory stop can be used by police officers to prevent and solve crimes, but it is important that the stop is conducted in a manner that respects the individual's rights and is based on reasonable suspicion.