See also the Wikipedia article for "online persona".
A persona or avatar is the represenative depiction of an individual on the Internet.
In art-based communities such as deviantArt or Route 50, members establish their personas through pictures or with a written description.
Usually, the word "persona" on its own carries the connotation of being a human persona, as nonhuman personae generally have their own terminology (e.g. fursona, Pokesona, ponysona, etc.)
The Persona Database group carries a reference list for users' various personae.
Although stories and drawings on Eevee's HQ often depicted members as human, only a few users had established human personae until the transition to Route 50, during which Pope's human persona helped to spread popularity of human personae. Xetaja's story, From the Desk of... also popularized human personae..