What is ArcGIS Portal/Online/Hub?

ArcGIS Portal (Portal for ArcGIS, now ArcGIS Enterprise) is a web-based mapping and collaboration platform that allows organizations to share maps, apps, and other geographic information with their users. ArcGIS Online is Esri's cloud-based GIS platform, offering similar functionality as ArcGIS Portal but hosted and managed by Esri. ArcGIS Hub is a community engagement platform built on ArcGIS that enables organizations to collaborate with internal and external stakeholders to address specific initiatives or projects. These technologies are commonly used for creating and sharing web maps, analyzing spatial data, building custom GIS applications, and facilitating collaboration among users.