Ok so imagine you are under investigation for murder.
This is not a murder you committed, you are completely innocent and you know it. You know you are innocent because the murder happened at the bowling alley, and you were at the mall seeing a movie when the person was killed.
You went to the mall with your best friend. They are one of the people closest to you, and they know everything about you, and what happened the night the murder occurred.
Before the movie, you took a couple videos and pictures of you and your best friend at one of the stores in the mall. These videos and pictures are time stamped on your phone for just a few minutes before and after the murder was committed.
You are sitting in an interrogation room, and the police ask to see the videos and pictures of you and your best friend at the mall, so they can discharge you and rule you out of the investigation.
Instead of unlocking your phone to show the cops the videos, you claim your 4th amendment rights to improper search and seizure, and tell the cops they need a warrant to get the videos. You refuse to unlock your phone, call your friend, or give the police their phone number so they can call her and ask what happened the night of the murder.
This is what trump suppprters mean when they say “he has executive privilege”