Its definitely older. I remember hearing about it around a job I had in 2017-2020, but it was already an established term by that time. Quote: 2013-2015: The

Its definitely older. I remember hearing about it around a job I had in 2017-2020, but it was already an established term by that time. Quote: 2013-2015: The concept of SSR in JavaScript frameworks emerged with React (released in 2013). Initially, it was referred to as "reconciliation" or "bootstrapping" — React would match the DOM with the virtual DOM. 2015: Around the release of React 0.14 and React 15 (2016), the term "hydration" began appearing in the React ecosystem to describe the process of attaching event listeners to server-rendered markup. The first known mention in React documentation and community discussions around 2015-2016 clarified that React would "hydrate" the HTML. This distinguished it from full re-rendering, which would discard the server-rendered DOM.