A more thorough explanation:

A pat-down search is a type of search conducted by a police officer where they pat down the outer surfaces of a person's clothing to look for weapons. This type of search is considered a search under the Fourth Amendment. Pat-down searches are usually done without a warrant and are only justified if the officer has reasonable suspicion that the person being searched is armed and dangerous.

For example, in the case of Rogue v. States, the court found that a police officer did not have reasonable suspicion to conduct a pat-down search of a vehicle passenger during a valid traffic stop because the officer lacked specific information about the passenger.

Pat-down searches are done to ensure the safety of the officer, and the search should not go beyond what is necessary to serve that purpose. If the officer feels an object during the pat-down that they reasonably suspect may be a weapon, they may remove it. The officer may also seize objects during a pat-down search if they reasonably believe it to be contraband.

Under certain circumstances, pat-down searches for weapons may be conducted without reasonable suspicion. For example, searches of persons boarding an airplane or entering a courthouse or other government building are generally permitted as long as the search does not go beyond what is necessary.