Start here. https://epiusers.help/t/rest-overview-novel/36260
TLDR; REST is an architectural idea used by many companies today to exchange data over the web infrastructure. In 10.1.600 (preview in .500), Epicor enabled a RESTful interface to Epicor. One of the goodies is OData access to many of your Epicor Resources. What the hell does that mean? For you, a user can have an Excel workbook log into Epicor (as themselves), run a BAQ, and populate a worksheet. But wait. If the user clicks Refresh in Excel, it reruns the BAQ and updates the worksheet with the latest data. No more copy/paste or Open with Excel! Sound interesting?
Mark W.