A Junior is a quasi-affectionate term for a newer RPer often used amongst the op staff in private.
Junior is not a term of derision, and nor is it a term strictly applying to the young. Although the younger players often do tend to be juniors, the condition can apply to anyone who is unfamiliar with roleplay's execution as a whole. The "junior" phase of a roleplayer's career can last a very long time, especially in an environment dominated by other juniors, which can be a serious problem upon Infinitas as of this article's writing.
A junior is defined by their understanding of narrative structure and how it is used in the day to day function of the RP - or more accurately, their lack thereof. It's perfectly natural for most of us, when we start RPing, to be unfamiliar with it as a form of actual storytelling. For the most part, it just seems - and often is - a way to relax at the end of the day by stepping into someone else's shoes and simply interacting with other people who are doing the same, without the burdens of an overarching story, conflict, or any pressure whatsoever.
While roleplaying for the sake of roleplaying can be fun, it often becomes tiring when there is no depth to it. Without a story, characters merely wander into each other at complete random to discuss things day to day, and there's only so much simulated conversation we can take part in before it becomes very boring. Naturally, the first thought of many is to spice things up by introducing things like magical abilities, transformations or found objects into things, but as detailed in the link above, these do not go very far, because their inclusion in and of itself does not make a narrative structure.
Part of the natural evolution out of the junior phase happens when the idea of telling stories and developing narratives on one's own begins to take hold. In this way, roleplay becomes less a mindless amusement and more about group storytelling. This greater understanding of the core of roleplaying often marks the progression of roleplaying from a way to waste time into something actually enjoyable.
Juniors are not to be scorned or derided, but rather encouraged to come up with their own plots and stories and ideas and execute them. They should be surrounded by an atmosphere of support and cooperation, and encouraged to develop and grow their ideas. We all start as juniors, and with care and support a junior can grow into a valuable and skilled storyteller.