Imagine you are playing hide and seek with your friends. You hide behind a tree and cover yourself with a big leaf so your friends can't see you. This is kind of like what masking is.
Now imagine you decide to peek out from behind the leaf to see where your friends are. When you peek out, your friends might be able to see you. This is kind of like what unmasking is.
Intelligence agencies are like secret hide and seek players who try to find out information about other countries or people. Sometimes, they need to hide their own identity so no one knows who they are. This is called masking. They could use fake names, wear disguises, or even create fake accounts on social media to hide their identity.
Now, let's say that the intelligence agency discovers some information that they need to share with someone else but they don't know who it belongs to. They might need to take off their mask to get a better look and find out who the information belongs to. This is called unmasking.
However, unmasking is not always allowed. It is only done when there is a good reason, like if there is a threat to the country or if it is necessary to protect someone's safety.
In summary, masking is like hiding during hide and seek, while unmasking is like peeking out from behind your hiding spot to see where your friends are. Intelligence agencies use masking to keep their identity secret and unmasking to find out information that is important for the safety of their country or people.