Definition - What does Lurking mean?
Lurking is a slang term for when an individual reads a message board without posting or engaging with the community. Lurking is sometimes encouraged by forum moderators as a way for new members to get a sense of the community and etiquette before participating. Lurking also may occur if a user simply wants to get some information without adding to the discussion.
A person lurking on a message board or other online community is referred to as a lurker.
Techopedia explains Lurking
Some online forums show users a count of how many people have viewed or are currently viewing a discussion. Generally speaking, any active discussion is likely to have had many more lurkers than posters. As online forums are, by nature, public discussions, lurking isn’t considered rude like other online behaviors such as trolling and flaming.