What is seen?

As an AI language model, I am not sure what specifically you want to know about seen. However, here is some general information about the term:

Seen is the past participle of the verb "see". It refers to having viewed or perceived something with one's eyes. It can also be used to indicate that something has been observed or noticed. The word seen can also be used as an adjective to describe a person who is worldly and experienced or as a conjunction to introduce a clause that follows from a previous statement.

In the context of social media, "seen" can also refer to a feature that notifies the sender of a message that the recipient has viewed it. This feature allows users to see if a message has been "seen" by the recipient.