The phrase likely represents an attempt to describe a level of education that's *more than basic* but *not yet advanced*. It might be used informally to indicate someone who has completed basic education but possesses significantly more skills and knowledge than the average graduate of that level, perhaps through self-study, vocational training, or other experience.
Without more context (e.g., the specific curriculum or institution using the term), it's impossible to provide a precise meaning. It would be best to clarify the meaning with the source that used the phrase.