Evidence packaging is a way to carefully collect and store important things that can tell us information about a crime.
Let's say someone steals a toy from you. The police officer needs to collect that toy as evidence. First, they will carefully pick up the toy with gloves on so they don't leave any of their own fingerprints on it. Then, they will put that toy in a special bag that keeps it safe from getting dirty or damaged while it is being taken to the lab to be studied.
Once the evidence is in the lab, scientists will use special tools and cameras to look closely at the toy to see if there are any fingerprints, hair, or other clues left behind by the thief. That way, they can try to figure out who stole the toy and catch them.
So, evidence packaging is basically a way for police officers to make sure that all the important clues from a crime scene are collected in a safe and careful way so that they can be studied later to try to solve the crime.