Since all kinds of open-source software are available to the public, open access to scholarly publications becomes a hot topic in educational institutions. Sometime, people consider them same, or even equal. I would reserve this view rather than argue with it. For me, I think they are different things, but they might be related each other at some point.
The reason that people argue it is that open access is challenging traditional scholarly publishing, e.g. university press. I would say publications published by university press usually come from both internal and external institutions. They do not only rely on campus publications, otherwise, they won’t survive.
Today, open access makes scholarly online communication possible at free of charge, it will tremendously change the way that scholars communicate historically. Scholars have more options to make their researches shared by the community globally if they hold the copyrights. They can easily reach people who have the same interests at no cost. This scholarly communication will bring innovation to the scholarly community. On the other side, we also need to establish a fair system to control the quality of scholarly publishing and make those peer-reviewed publications available to more researchers at no cost.