Answer:
include a warrant and be based on probable cause.
Step-by-step explanation:
The fourth Amendment was created to prevent the abuse of power from the police department. Before the fourth amendment was created, the police had the right to conduct a search to citizens' home at any given time and place. This leaves a lot of opportunities for them to plant evidence and disrupt the right of privacy.
After the amendment, Police can no longer do that. In order to search a private property, they need to gain a warrant (which is basically a permit given by the court) or maybe the have a strong basis to believe that a citizen is in danger. (For example, if police heard a gun shot from a private property, that police can conduct a search without a warrant)