The new Selenium Grid in Selenium 4 is a refreshed mechanism that allows distributing tests across a fleet of machines, building upon the concept of the original Selenium Farm at Google and the Open Source implementation by Philippe Haringou. The old Grid had limitations such as only speaking the original Selenium RC protocol and requiring manual configuration, whereas the new Grid aims to be easier to work on and maintain, merging servers into a single unit, and taking advantage of modern infrastructure technologies like Docker and Kubernetes. It introduces a router, session queue, distributor, nodes, and a message bus, with the ability to run in standalone or traditional Hub and Node modes, and also supports a fully distributed mode for scalability. The new Grid also adopts Open Telemetry for observability and provides a GraphQL endpoint for more flexibility and querying specific areas of interest.