What is mean by poke back?

"Poke back" generally refers to the act of responding to someone who has poked you, particularly in social media contexts like Facebook, where a "poke" is a way to get someone's attention or to initiate interaction. It can also imply reciprocating a gesture or action, often in a playful or lighthearted manner. Essentially, it's about engaging with someone in response to their initial contact.