Hi @Mercury Man ,
If you want to get all users of site then
_spPageContextInfo.webAbsoluteUrl + "/_api/Web/SiteUsers"
If You want to display information of User in site then
_spPageContextInfo.webAbsoluteUrl + "/_api/Web/SiteUserInfoList"
If you want to get the properties of the current user on the site then you can use :
_spPageContextInfo.webAbsoluteUrl + "/_api/Web/currentUser"
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