on Jane Friedman site:
Literary magazines, also called literary journals or lit mags, are devoted to short-form creative writing. What distinguishes them is what they publish (a single genre or a mix of genres), how often they publish (annually, biannually, quarterly, monthly), and their medium of publication (print only, online only, combination of print and online).
Some magazines are affiliated with universities, giving them the security of funding and editorial or production staff culled from professors or students. Others are independently funded by individuals or grants. But what they have in common is their mission: publish the best writing of today. They are a labor of love, intending to gather our cultural milieu in the forms of prose, pictures and poetry with little concern for financial or commercial payback. Competitive as they are to get into, they represent a publishing milestone for literary writers in particular.