Peer review is a fundamental pillar of the dissemination and validation of scientific knowledge. A considerable portion of this process operates on a voluntary basis, involving contributions from paper referees to journal editors. While there are commercial journals that employ professional editors, the core reviewing process still relies on unpaid researchers who offer their time and expertise.
It is my belief that peer review plays an indispensable role in the training and professional development of every scientist. It fosters the ability to understand and critically evaluate the research contributions of fellow scholars within the scientific community. Some of the younger readers may wonder how to engage in peer review, so let me offer one piece of advice. Many journals actively (and sometimes desperately) seek qualified reviewers, often advertising opportunities through their websites, social media channels, etc. In addition to that, graduate students can assist their advisors with peer review activities. Some journals even encourage such involvement and offer credit.