"Scholarly Communication" describes the system by which researchers share the results of their research with their colleagues. No new knowledge is created in a vacuum. Instead it is built upon the existing ideas and research of others. Sharing these ideas and research effectively, then, is a vital component of the creation of new knowledge.
Publishing the results of one's research in a traditional academic journal serves to broadly disseminate those results to one's colleagues around the world. However, this system of scholarly communication is currently in crisis.
For several hundred years, scholarly journals were disseminated in print. However, the rise of digital publication has irrevocably transformed the landscape of scholarly communication. In the digital age, we can reduce the costs of sharing our ideas by eliminating materials, printing, and disseminating physical journals. However, the prices of many journal subscriptions continue to increase dramatically, often at several times the rate of inflation.
As a result, many libraries, the primary purchasers of scholarly journals, have been forced to either cancel subscriptions, or reduce the rate of collection of other materials. This means that the audience for your research is effectively limited.
This is further compounded by the fact that most journals require researchers to surrender some, if not all, of their copyright to their works. That, in turn, prevents the open sharing of research with colleagues who may not be able to pay for pricey subscriptions.
There are alternatives to the traditional scholarly communication system, though, and you can make a difference.