Searches and seizures are actions that can be carried out as part of a criminal case. A search happens when the police do things like looking through a person’s belongings or listening in on their phone calls. A seizure is when the police actually take physical possession of something that belongs to a suspect. Searches and seizures are legal under the US Constitution, but only in certain circumstances.
In general, a search or seizure may only be carried out by the police if they have a warrant to do so. The warrant has to state exactly what they are looking for. That means that the police cannot simply get a warrant to look in your house and see what you might have. They have to specify what they are looking for and they have to look only in places where it might be found.
Searches and seizures can be conducted without a warrant in certain cases. Even then, however, the police need to have probable cause to carry out these procedures.
The term “searches and seizures,” then, applies to actions that the police take in the course of a criminal investigation. They must conduct the searches and seizures legally in order to be allowed to use any evidence they find in court.