Some of the biggest players in scientific communication are scientific publishers. They provide the technical infrastructure that journals need to handle manuscript submission, peer review and revision, copy editing, and publication. The publisher also provides the financial ability for journals to employ editors (to commission articles), to shape and check the articles, and to distribute the finished product to subscribers.
The scientific publishing market is complex and dynamic. Journals change publishers, and publishers acquire or merge with competitors. It likely isn't surprising that the market is largely dominated by six large publishing houses: Elsevier, Wiley-Blackwell, American Chemical Society, Taylor & Francis, Springer Nature, and SAGE. The proportion of the scientific output published in journals under their ownership has risen steadily over the past 40 years, and they control more than 50% of the market. Elsevier is the largest, with approximately 16% of the total market and more than 3000 academic journals.