The police arrested the suspect late last night. [Active: The subject “police” performs the action “arrested.”]
The suspect was arrested by police late last night. [Passive: The subject “suspect” is being acted upon.]
The archaeologist found an ancient artifact. [Active: The subject “archaeologist” performs the action “found.”]
An ancient artifact was found by the archaeologist. [Passive: The subject “artifact” is being acted upon.]
Miriam folded the sheets and pillowcases. [Active: The subject “Miriam” performs the action “folded.”]
The pillowcases were folded by Miriam. [Passive: The subject “pillowcases” is being acted upon.]